https://github.com/ogunerkutay/windows-app-data-storage-guidelines

https://github.com/ogunerkutay/windows-app-data-storage-guidelines

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• Host: GitHub
• URL: https://github.com/ogunerkutay/windows-app-data-storage-guidelines
• Owner: ogunerkutay
• Created: 2025-09-18T11:53:38.000Z (19 days ago)
• Default Branch: main
• Last Pushed: 2025-09-18T12:05:55.000Z (19 days ago)
• Last Synced: 2025-09-18T13:45:58.031Z (19 days ago)
• Size: 61.5 KB
• Stars: 0
• Watchers: 0
• Forks: 0
• Open Issues: 1
• Metadata Files:
  • Readme: README.md

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README

          
# 📂 Windows App Data Storage Guidelines

A quick reference for where to store **application files** on Windows.  

Following these conventions keeps apps clean, avoids permission issues, and aligns with industry standards.

---

## 🗂 Key Directories

| Folder | Usage | Access |

|--------|-------|--------|

| **AppData\Roaming** | User-specific **settings, configs, small data** that should move with the user across domain PCs. | `%APPDATA%` → `C:\Users\\AppData\Roaming` |

| **AppData\Local** | User-specific **non-roaming data**, like caches, logs, temp DBs. Stays on that PC. | `%LOCALAPPDATA%` → `C:\Users\\AppData\Local` |

| **AppData\Local\Temp** | Short-lived, disposable files. OS may auto-delete. | `%TEMP%` → `C:\Users\\AppData\Local\Temp` |

| **ProgramData** | Machine-wide, non-user-specific data. Shared configs, DBs, license info. | `%PROGRAMDATA%` → `C:\ProgramData` |

| **Documents** | Files visible to the user (documents, projects). | `%USERPROFILE%\Documents` |

| **Registry** | Small settings, app state, licensing keys. | `HKCU\Software\` (per-user)
`HKLM\Software\` (machine-wide) |

---

## 🔑 Rules of Thumb

- **Settings / Configs → Roaming**  

- **Cache / Logs / Big Files → Local**  

- **Shared Data → ProgramData**  

- **User Documents → Documents**  

- **Temporary Files → Temp**  

- **Small Key-Values → Registry**

❌ Never write to `Program Files` at runtime (requires admin & breaks UAC rules).

---

📌 Example App File Layout

![Layout](https://github.com/user-attachments/assets/1623be38-c569-49a1-aa59-6e0ab057ffe4)

---

## 🛠 Accessing Paths in .NET (C#)

```csharp

// User-specific folders

string roaming = Environment.GetFolderPath(Environment.SpecialFolder.ApplicationData);

string local = Environment.GetFolderPath(Environment.SpecialFolder.LocalApplicationData);

string temp = Path.GetTempPath();

// Example usage

string settingsPath = Path.Combine(roaming, "MyApp", "settings.json");

string cacheFolder = Path.Combine(local, "MyApp", "cache");

✅ Always use Environment.SpecialFolder — don’t hardcode paths.

✅ Best Practices

Respect Windows conventions (don’t confuse roaming/local).

Store only what’s necessary (avoid bloat in roaming).

Use registry only for small configs, not data storage.

Clean up temp files after use.

Use installer/project setup to create default directories.

📖 Quick mental model:

Roaming = “Settings I want everywhere”

Local = “Stuff that belongs only to this PC”

Temp = “Safe to throw away”

ProgramData = “Shared across users”

Registry = “Tiny key/value pairs”