Modern developer tools are storage monsters. If you use tools like: Cursor VS Code Docker Node.js AI/ML frameworks Electron apps Local LLM tools Low storage SSD system OR Any general apps …you’ve probably noticed your C: drive slowly dying. Even when apps are installed on another SSD, Windows still stores huge amounts of cache and configuration data inside: C:\Users\\AppData Over time this becomes a problem: SSD fills up Windows updates fail Performance degrades AI model caches explode Docker eats tens of GB Electron apps duplicate Chromium storage everywhere I got tired of manually moving folders and creating symlinks. So I built a safer automated PowerShell migration utility. The utility safely moves heavy AppData folders from C: to another drive and replaces them with NTFS junctions. Applications continue working normally. Windows still thinks the folders exist on C:. But the actual data lives elsewhere. Before: C:\Users\prath\AppData\Local\Cursor After: C:\Users\prath\AppData\Local\Cursor -> D:\APPDATA_REDIRECT\Cursor\Local\Cursor To the app: nothing changed To your SSD: huge storage recovered NTFS junctions are filesystem-level redirects built into Windows. They are: fast transparent stable compatible with most Windows applications Unlike shortcuts, applications treat junctions as real folders. This makes them perfect for: caches package managers AI model storage extension folders Electron app data Docker layers The script: scans folders verifies paths creates migration snapshots transfers data creates junctions validates success rolls back automatically on failure Already migrated folders are detected automatically: [ALREADY MIGRATED] [-] [Roaming] C:\Users\prath\AppData\Roaming\Cursor -> D:\APPDATA_REDIRECT\Cursor\Roaming\Cursor No duplicate work. No accidental corruption. You choose exactly what gets migrated: [1] [Local] C:\Users\prath\AppData\Local\Cursor [2] [Roaming] C:\Users\prath\AppData\Roaming\Cursor Supports: single selection multiple selection migrate all robocopy Instead of basic file copy operations, the tool uses: robocopy /E /MOVE Why this matters: resilient transfers retries metadata preservation large-folder reliability safer than naive copy/delete If anything fails: junction creation move operation verification …the script automatically restores the original folder. This is critical when dealing with live application data. This is especially useful for developers and AI engineers. Extensions and AI indexes become massive over time. Move: AppData\Roaming\Cursor AppData\Local\Cursor Docker Desktop can consume absurd amounts of SSD space. Move: AppData\Local\Docker Package managers and caches grow endlessly. Useful targets: npm-cache pnpm-store yarn cache Perfect for: model downloads embeddings vector indexes Hugging Face cache Ollama storage CUDA caches The workflow is designed to be defensive and recoverable. The script searches: AppData\Local AppData\Roaming AppData\LocalLow and even: C:\Users\\. Before migration it records: file count destination size state This enables recovery logic later. Using: robocopy /MOVE The original directory is removed only after successful transfer. PowerShell creates: New-Item -ItemType Junction Applications continue working normally. The script checks: junction exists target exists transfer succeeded If validation fails: rollback begins automatically ================================================== STARTING MIGRATION ================================================== Migrating: C:\Users\prath\AppData\Local\Cursor [+] Files moved successfully [+] Junction created C:\Users\prath\AppData\Local\Cursor -> D:\APPDATA_REDIRECT\Cursor\Local\Cursor Do NOT migrate: Windows system folders Microsoft core directories active system temp folders random unknown services Always: close applications first stop Docker if migrating Docker stop AI servers before migration run PowerShell as Administrator The script already blocks some dangerous paths automatically. Windows NTFS filesystem PowerShell Administrator privileges Run PowerShell as Administrator: powershell -ExecutionPolicy Bypass -File migration.ps1 On my system this recovered: tens of GB from Cursor massive Docker cache usage AI model storage clutter Electron app duplication Without breaking a single app. This approach is especially useful on: laptops with small SSDs dev machines AI workstations dual-drive setups systems using local LLMs Windows AppData management becomes painful once you start working with modern development and AI tooling. The problem isn’t installation size anymore. It’s hidden storage growth. NTFS junctions are one of the cleanest solutions available on Windows, and automating the process safely makes a huge difference. If you’re constantly fighting low SSD space while doing development, AI, or Docker work — this approach can save your setup. migration.ps1 README.md Windows AppData Junction Migrator Gist 🔗 License MIT License