Do You Need WinRAR to Put Games on a PSP?

No. WinRAR is a file archiver (`.rar`, `.zip`, `.7z`). It is **not required** to install games on a PSP. You only need it if your downloaded game files are *packed inside a `.rar` archive* — and even then, 7-Zip (free, open-source) or Windows built-in ZIP support handles it fine.

Actual PSP Game Formats

• .ISO — Full uncompressed disc image (standard).
• .CSO — Compressed ISO (smaller, slight load lag on slow Memory Sticks).
• .PBP — Homebrew / PS1 Classics / Minis (signed or unsigned).

What You Actually Need

1. PSP (1000/2000/3000/Go/E1000) on **Custom Firmware (CFW)** or **HEN (6.61 Infinity / 6.61 HEN)**. Official Firmware (OFW) cannot run ISOs/CSOs.
2. Memory Stick Pro Duo (PSP 1000–3000) or **MicroSD + Pro Duo Adapter** (cheaper, faster). Max tested: 512 GB (dual 256 GB adapters).
3. USB Cable / Card Reader to transfer files to `MS0:/ISO/` or `MS0:/GAME/`.
4. ISO Tool / PSP Filer / CXMB (optional, for converting/compressing ISOs → CSO on device).

Step-by-Step (CFW/HEN)

1. Connect PSP via USB or remove Memory Stick → Card Reader.
2. Create folder `ISO` at root of Memory Stick (`X:/ISO/`).
3. Copy `.ISO` or `.CSO` files there.
4. Disconnect. On PSP: Game → Memory Stick → Game appears.
5. If not: Run **ISO Tool** → "Refresh" or rebuild database.

PSP Go Specifics

• 16 GB Internal Flash only (no Memory Stick slot).
• Use **Media Go** (PC) or **USB Mass Storage Mode** to copy ISOs to `ef0:/ISO/`.
• Requires **6.61 Infinity** (permanent CFW) for ISO support.

Legal Note

Downloading ISOs for games you do not own is piracy. Dumping your own UMDs to ISO (using UMD Dumper on CFW) is legal archival in many jurisdictions.