docs: add troubleshooting guide

docs/Troubleshooting.md

@@ -0,0 +1,105 @@
+# Windows Calculator Troubleshooting Guide
+
+This guide helps users solve common problems with Windows Calculator.
+
+## Common Issues
+
+### Calculator Won't Open
+
+**Symptom:** Double-clicking Calculator does nothing or shows an error.
+
+**Solutions:**
+1. **Restart your computer** - Sometimes a simple reboot resolves loading issues.
+2. **Check for updates** - Install the latest Windows updates from Settings > Windows Update.
+3. **Reset Calculator:**
+   - Go to Settings > Apps > Installed Apps
+   - Find Calculator and click "Modify" or "Repair"
+   - If that doesn't work, click "Uninstall" then reinstall from Microsoft Store.
+
+### Display or Rendering Issues
+
+**Symptom:** Calculator display is blank, distorted, or shows incorrect values.
+
+**Solutions:**
+1. **Restart Calculator** - Close and reopen the app.
+2. **Update your display drivers** - Visit your graphics card manufacturer's website.
+3. **Check scaling settings** - Right-click Calculator > Properties > Compatibility > Change high DPI settings.
+
+### Currency Converter Shows Wrong Values
+
+**Symptom:** Currency conversions seem incorrect or outdated.
+
+**Solutions:**
+1. Currency rates are updated periodically—check your internet connection.
+2. Rates in developer builds use mock data (shows planetary names instead of currencies).
+3. For accurate rates, use the Microsoft Store version of Calculator.
+
+### Unit Converter Errors
+
+**Symptom:** Unit conversions give unexpected results.
+
+**Solutions:**
+1. Verify you're selecting the correct unit types (e.g., temperature scale).
+2. Check if you need to use the scientific mode for advanced conversions.
+3. Some conversions are approximate—use for estimation only.
+
+### Memory or History Not Working
+
+**Symptom:** Memory (M+, M-, MR) buttons don't work or history is empty.
+
+**Solutions:**
+1. **Clear memory:** Click "MC" to clear stored memory values.
+2. **Enable history:** Go to Settings > History and ensure it's turned on.
+3. **Restart the app** to refresh the state.
+
+### Performance Issues
+
+**Symptom:** Calculator runs slowly or lags during calculations.
+
+**Solutions:**
+1. **Close other apps** to free up system resources.
+2. **Check for background updates** - Pause Windows updates while using Calculator.
+3. **Ensure sufficient disk space** - At least 100MB recommended.
+
+### Keyboard Shortcuts Not Working
+
+**Symptom:** Pressing shortcuts like `Alt+2` for scientific mode does nothing.
+
+**Solutions:**
+1. Calculator must be the active window for shortcuts to work.
+2. Some shortcuts require Administrator mode.
+3. Check keyboard language settings in Windows.
+
+## Installation Issues
+
+### Cannot Install from Microsoft Store
+
+**Solutions:**
+1. Sign out and back into Microsoft Store.
+2. Clear Microsoft Store cache:
+   - Press `Win+R`, type `wsreset.exe`, press Enter.
+3. Check your date/time settings are correct.
+
+### Builds from GitHub Don't Work
+
+The GitHub version requires:
+- Windows 11, build 22000 or newer
+- Visual Studio 2022 with UWP workload
+- Latest Windows 11 SDK
+
+See [README.md](README.md) for full prerequisites.
+
+## Getting More Help
+
+- **Report bugs:** Use Feedback Hub or open an issue on GitHub
+- **Feature requests:** Open an issue on GitHub with "feature" label
+- **Contribute:** See [CONTRIBUTING.md](../CONTRIBUTING.md)
+
+## Diagnostic Data
+
+If issues persist, you may be asked to enable diagnostic data:
+1. Open Calculator
+2. Go to Settings > Privacy
+3. Enable diagnostic data collection
+
+This helps Microsoft investigate issues.