Can You Install Windows 7 on a PSP?

No. It is technically impossible.

Fundamental Incompatibilities

• CPU Architecture: PSP uses MIPS (Allegrex, 333 MHz). Windows 7 requires x86/x64 (Intel/AMD). Instruction sets are mutually unintelligible.
• RAM: PSP has 32–64 MB. Windows 7 minimum is 1 GB (32-bit) / 2 GB (64-bit).
• Storage: PSP max Memory Stick Pro Duo = 32 GB (rare/expensive). Win 7 needs 16–20 GB minimum.
• GPU/Drivers: PSP's GE (Graphics Engine) has no Windows driver model; no HAL exists.
• Input/Output: No keyboard/mouse/standard display interface; Win 7 shell unusable.

What You Can Do on a PSP

• Custom Firmware (CFW) / HEN: Run homebrew emulators (NES, SNES, Genesis, PS1), ports (Doom, Quake, Cave Story), media players, plugins.
• PS1 Classics / PSP ISOs: Play backups of games you own via Memory Stick.
• Remote Play: Stream PS3/PS4/PC (via moonlight/chiaki) to PSP screen—this lets you "run Windows apps" remotely.
• Linux (µClinux): Experimental, command-line only, no GUI, extremely limited—academic curiosity, not usable.

For portable Windows gaming, buy a Steam Deck, ROG Ally, or GPD Win—they run actual Windows/Linux x86 games natively.