diff --git a/composeApp/build.gradle.kts b/composeApp/build.gradle.kts
index a15f29e..e2b65ae 100644
--- a/composeApp/build.gradle.kts
+++ b/composeApp/build.gradle.kts
@@ -2,6 +2,7 @@ import org.jetbrains.compose.desktop.application.dsl.TargetFormat
 
 plugins {
     alias(libs.plugins.kotlinMultiplatform)
+    alias(libs.plugins.kotlinSerialization)
     alias(libs.plugins.composeMultiplatform)
     alias(libs.plugins.composeCompiler)
 }
@@ -23,6 +24,9 @@ kotlin {
             implementation(libs.androidx.lifecycle.runtime.compose)
             implementation(libs.androidx.navigation.compose)
             implementation(libs.androidx.datastore.preferences)
+
+            implementation("org.jetbrains.kotlinx:kotlinx-serialization-json:1.7.3")
+
         }
 
         commonTest.dependencies {
@@ -55,5 +59,10 @@ compose.desktop {
             // Use system theming fot the app toolbars.
             jvmArgs("-Dapple.awt.application.appearance=system")
         }
+
+        buildTypes.release.proguard {
+            obfuscate.set(false) // Obfuscation crash when try to use datastore.
+            configurationFiles.from(project.file("compose-desktop.pro"))
+        }
     }
 }
diff --git a/composeApp/compose-desktop.pro b/composeApp/compose-desktop.pro
new file mode 100644
index 0000000..a9bbc0e
--- /dev/null
+++ b/composeApp/compose-desktop.pro
@@ -0,0 +1,12 @@
+## Data Store old dependancies not removed properly.
+-dontwarn okio.AsyncTimeout$Watchdog
+
+-keep class androidx.compose.runtime.** { *; }
+-keep class androidx.collection.** { *; }
+-keep class androidx.lifecycle.** { *; }
+
+# We're excluding Material 2 from the project as we're using Material 3
+-dontwarn androidx.compose.material.**
+
+# Kotlinx coroutines rules seems to be outdated with the latest version of Kotlin and Proguard
+-keep class kotlinx.coroutines.** { *; }
\ No newline at end of file
diff --git a/composeApp/src/commonMain/composeResources/values/strings.xml b/composeApp/src/commonMain/composeResources/values/strings.xml
index 0d81a5f..896deb3 100644
--- a/composeApp/src/commonMain/composeResources/values/strings.xml
+++ b/composeApp/src/commonMain/composeResources/values/strings.xml
@@ -10,9 +10,9 @@
 
     <string name="character_sheet_edit__title">Création de personnage</string>
     <string name="character_sheet_edit__name_placeholder">Nom</string>
-    <string name="character_sheet_edit__add_roll_action">Ajouter un lancé</string>
+    <string name="character_sheet_edit__add_roll_action">Ajouter un lancer</string>
     <string name="character_sheet_edit__save_action">Sauvegarder</string>
-    <string name="character_sheet_edit__characteristics__title">Charactéristiques</string>
+    <string name="character_sheet_edit__characteristics__title">Caractéristiques</string>
     <string name="character_sheet_edit__characteristics__str">Force</string>
     <string name="character_sheet_edit__characteristics__dex">Dextérité</string>
     <string name="character_sheet_edit__characteristics__con">Constitution</string>
@@ -20,14 +20,14 @@
     <string name="character_sheet_edit__characteristics__int">Intelligence</string>
     <string name="character_sheet_edit__characteristics__pow">Pouvoir</string>
     <string name="character_sheet_edit__characteristics__cha">Charisme</string>
-    <string name="character_sheet_edit__sub_characteristics__title">Charactéristiques dérivées</string>
+    <string name="character_sheet_edit__sub_characteristics__title">Caractéristiques dérivées</string>
     <string name="character_sheet_edit__sub_characteristics__movement">Déplacement</string>
     <string name="character_sheet_edit__sub_characteristics__hit_point">Points de vie</string>
     <string name="character_sheet_edit__sub_characteristics__power_point">Points de pouvoir</string>
     <string name="character_sheet_edit__sub_characteristics__damage_bonus">Bonus aux dégats</string>
     <string name="character_sheet_edit__sub_characteristics__armor">Armure</string>
-    <string name="character_sheet_edit__skills__title">Compétances</string>
-    <string name="character_sheet_edit__skills__add_action">Ajouter une compétance</string>
+    <string name="character_sheet_edit__skills__title">Compétences</string>
+    <string name="character_sheet_edit__skills__add_action">Ajouter une compétence</string>
     <string name="character_sheet_edit__skills__combat">Bagarre</string>
     <string name="character_sheet_edit__skills__dodge">Esquive</string>
     <string name="character_sheet_edit__skills__grab">Saisie</string>
@@ -56,7 +56,7 @@
     <string name="character_sheet__characteristics__int">Intelligence</string>
     <string name="character_sheet__characteristics__pow">Pouvoir</string>
     <string name="character_sheet__characteristics__cha">Charisme</string>
-    <string name="character_sheet__sub_characteristics__title">Charactéristiques dérivées</string>
+    <string name="character_sheet__sub_characteristics__title">Caractéristiques dérivées</string>
     <string name="character_sheet__sub_characteristics__movement">Déplacement</string>
     <string name="character_sheet__sub_characteristics__hit_point">Points de vie</string>
     <string name="character_sheet__sub_characteristics__power_point">Points de pouvoir</string>
diff --git a/composeApp/src/commonMain/kotlin/com/pixelized/desktop/lwa/business/RollUseCase.kt b/composeApp/src/commonMain/kotlin/com/pixelized/desktop/lwa/business/RollUseCase.kt
index a0a67ec..a6f0739 100644
--- a/composeApp/src/commonMain/kotlin/com/pixelized/desktop/lwa/business/RollUseCase.kt
+++ b/composeApp/src/commonMain/kotlin/com/pixelized/desktop/lwa/business/RollUseCase.kt
@@ -24,21 +24,21 @@ object RollUseCase {
 
     fun roll(characterSheet: CharacterSheet, roll: String): Int {
         println(roll)
-        return diceParser.findAll(roll).sumOf {
-            val (sign, modifier, quantity, faces) = it.destructured
+        return diceParser.findAll(roll).sumOf { match ->
+            val (sign, modifier, quantity, faces) = match.destructured
             ((if (sign == "-") -1 else 1) * roll(
                 quantity = quantity.toInt(),
                 faces = faces.toInt()
             )).also {
                 println("roll ${sign}${quantity}d${faces} -> $it")
             }
-        } + flatParser.findAll(roll).sumOf {
-            val (sign, value) = it.destructured
+        } + flatParser.findAll(roll).sumOf { match ->
+            val (sign, value) = match.destructured
             ((if (sign == "-") -1 else 1) * value.toInt()).also {
                 println("flat: ${sign}${value} -> $it")
             }
-        } + paramParser.findAll(roll).sumOf {
-            val (sign, param) = it.destructured
+        } + paramParser.findAll(roll).sumOf { match ->
+            val (sign, param) = match.destructured
             (if (sign == "-") -1 else 1) * when (param) {
                 "BDGT" -> diceParser.findAll(characterSheet.damageBonus).sumOf {
                     val (sign, modifier, quantity, faces) = it.destructured
diff --git a/composeApp/src/commonMain/kotlin/com/pixelized/desktop/lwa/createDataStore.kt b/composeApp/src/commonMain/kotlin/com/pixelized/desktop/lwa/createDataStore.kt
index fb5009c..b54706d 100644
--- a/composeApp/src/commonMain/kotlin/com/pixelized/desktop/lwa/createDataStore.kt
+++ b/composeApp/src/commonMain/kotlin/com/pixelized/desktop/lwa/createDataStore.kt
@@ -3,8 +3,18 @@ package com.pixelized.desktop.lwa
 import androidx.datastore.core.DataStore
 import androidx.datastore.preferences.core.PreferenceDataStoreFactory
 import androidx.datastore.preferences.core.Preferences
+import com.pixelized.desktop.lwa.utils.OperatingSystem
 import okio.Path.Companion.toPath
 
 fun createDataStore(producePath: () -> String): DataStore<Preferences> {
     return PreferenceDataStoreFactory.createWithPath(produceFile = { producePath().toPath() })
+}
+
+fun dataStorePath(): String {
+    val root = when {
+        OperatingSystem.isWindows() -> "${OperatingSystem.home}\\AppData\\Roaming\\Pixelized\\"
+        OperatingSystem.isMacintosh() -> ""
+        else -> ""
+    }
+    return "${root}characterssheet.preferences_pb"
 }
\ No newline at end of file
diff --git a/composeApp/src/commonMain/kotlin/com/pixelized/desktop/lwa/repository/characterSheet/CharacterSheet.kt b/composeApp/src/commonMain/kotlin/com/pixelized/desktop/lwa/repository/characterSheet/CharacterSheet.kt
index f473606..9aa5756 100644
--- a/composeApp/src/commonMain/kotlin/com/pixelized/desktop/lwa/repository/characterSheet/CharacterSheet.kt
+++ b/composeApp/src/commonMain/kotlin/com/pixelized/desktop/lwa/repository/characterSheet/CharacterSheet.kt
@@ -1,7 +1,8 @@
 package com.pixelized.desktop.lwa.repository.characterSheet
 
-import java.io.Serializable
+import kotlinx.serialization.Serializable
 
+@Serializable
 data class CharacterSheet(
     val id: String,
     val name: String,
@@ -29,16 +30,17 @@ data class CharacterSheet(
     val magics: List<Skill>,
     // attack
     val rolls: List<Roll>,
-) : Serializable {
-
+) {
+    @Serializable
     data class Skill(
         val label: String,
         val value: Int,
         val used: Boolean,
-    ) : Serializable
+    )
 
+    @Serializable
     data class Roll(
         val label: String,
         val roll: String,
-    ) : Serializable
+    )
 }
\ No newline at end of file
diff --git a/composeApp/src/commonMain/kotlin/com/pixelized/desktop/lwa/repository/characterSheet/CharacterSheetPreference.kt b/composeApp/src/commonMain/kotlin/com/pixelized/desktop/lwa/repository/characterSheet/CharacterSheetPreference.kt
index 5bdb152..8357108 100644
--- a/composeApp/src/commonMain/kotlin/com/pixelized/desktop/lwa/repository/characterSheet/CharacterSheetPreference.kt
+++ b/composeApp/src/commonMain/kotlin/com/pixelized/desktop/lwa/repository/characterSheet/CharacterSheetPreference.kt
@@ -2,20 +2,20 @@ package com.pixelized.desktop.lwa.repository.characterSheet
 
 import androidx.datastore.core.DataStore
 import androidx.datastore.preferences.core.Preferences
-import androidx.datastore.preferences.core.byteArrayPreferencesKey
 import androidx.datastore.preferences.core.edit
-import com.pixelized.desktop.lwa.utils.extention.fromByteArray
-import com.pixelized.desktop.lwa.utils.extention.toByteArray
+import androidx.datastore.preferences.core.stringPreferencesKey
 import kotlinx.coroutines.flow.Flow
 import kotlinx.coroutines.flow.first
 import kotlinx.coroutines.flow.map
+import kotlinx.serialization.encodeToString
+import kotlinx.serialization.json.Json
 
 class CharacterSheetPreference(
     private val dataStore: DataStore<Preferences>,
 ) {
     suspend fun save(sheets: List<CharacterSheet>) {
         dataStore.edit {
-            it[characterSheetKey] = sheets.toByteArray()
+            it[characterSheetKey] = Json.encodeToString(sheets)
         }
     }
 
@@ -25,11 +25,13 @@ class CharacterSheetPreference(
 
     fun loadFlow(): Flow<List<CharacterSheet>> {
         return dataStore.data.map {
-            it[characterSheetKey]?.fromByteArray<List<CharacterSheet>>() ?: emptyList()
+            it[characterSheetKey]?.let { json ->
+                Json.decodeFromString<List<CharacterSheet>>(json)
+            } ?: emptyList()
         }
     }
 
     companion object {
-        private val characterSheetKey = byteArrayPreferencesKey("CharacterSheetsPrefKey")
+        private val characterSheetKey = stringPreferencesKey("CharacterSheetsPrefKey")
     }
 }
\ No newline at end of file
diff --git a/composeApp/src/commonMain/kotlin/com/pixelized/desktop/lwa/repository/characterSheet/CharacterSheetRepository.kt b/composeApp/src/commonMain/kotlin/com/pixelized/desktop/lwa/repository/characterSheet/CharacterSheetRepository.kt
index 711c9be..28c938b 100644
--- a/composeApp/src/commonMain/kotlin/com/pixelized/desktop/lwa/repository/characterSheet/CharacterSheetRepository.kt
+++ b/composeApp/src/commonMain/kotlin/com/pixelized/desktop/lwa/repository/characterSheet/CharacterSheetRepository.kt
@@ -1,6 +1,7 @@
 package com.pixelized.desktop.lwa.repository.characterSheet
 
 import com.pixelized.desktop.lwa.createDataStore
+import com.pixelized.desktop.lwa.dataStorePath
 import kotlinx.coroutines.CoroutineScope
 import kotlinx.coroutines.Dispatchers
 import kotlinx.coroutines.flow.SharingStarted
@@ -10,9 +11,8 @@ import kotlinx.coroutines.flow.stateIn
 
 object CharacterSheetRepository {
     private val scope = CoroutineScope(Dispatchers.IO)
-
     private val preferences = CharacterSheetPreference(
-        dataStore = createDataStore { "characterssheet.preferences_pb" }
+        dataStore = createDataStore { dataStorePath() }
     )
 
     private val sheets = preferences.loadFlow()
diff --git a/composeApp/src/commonMain/kotlin/com/pixelized/desktop/lwa/utils/SystemExt.kt b/composeApp/src/commonMain/kotlin/com/pixelized/desktop/lwa/utils/SystemExt.kt
new file mode 100644
index 0000000..e43af3e
--- /dev/null
+++ b/composeApp/src/commonMain/kotlin/com/pixelized/desktop/lwa/utils/SystemExt.kt
@@ -0,0 +1,14 @@
+package com.pixelized.desktop.lwa.utils
+
+object OperatingSystem {
+    private val name get() = System.getProperty("os.name")
+
+    val home: String
+        get() = when {
+            isWindows() -> System.getProperty("user.home")
+            else -> ""
+        }
+
+    fun isWindows(): Boolean = name.contains("win", ignoreCase = true)
+    fun isMacintosh(): Boolean = name.contains("mac", ignoreCase = true)
+}
diff --git a/gradle/libs.versions.toml b/gradle/libs.versions.toml
index 74c55c5..c40d174 100644
--- a/gradle/libs.versions.toml
+++ b/gradle/libs.versions.toml
@@ -23,4 +23,5 @@ kotlinx-coroutines-swing = { group = "org.jetbrains.kotlinx", name = "kotlinx-co
 [plugins]
 composeMultiplatform = { id = "org.jetbrains.compose", version.ref = "compose-multiplatform" }
 composeCompiler = { id = "org.jetbrains.kotlin.plugin.compose", version.ref = "kotlin" }
+kotlinSerialization = { id = "org.jetbrains.kotlin.plugin.serialization", version.ref = "kotlin" }
 kotlinMultiplatform = { id = "org.jetbrains.kotlin.multiplatform", version.ref = "kotlin" }
\ No newline at end of file