This is Windows 95 emulating on the PSP using DOSBox, runs 3x faster than PSP Bochs. It is compatible with PSP Slim, so all PSP with official firmware 1.5 that has been kxploit patched or custom firmware can do this.
I’VE GOT THESE INFORMATION FROM THIS WEBPAGE: http://djkman.freesmfhosting.com/index.php/topic,8.0.html

UPDATED! FIX ERROR WHERE IT SAYS “MS0:/PSP/GAME4XX/DOSBOX DOES NOT EXIST”, THANKS TO SPEEDEMON10!

Requirements:
*PSP(DUH!)
*PSP with official firmware 1.50 with kxploit patched or any custom firmware
*Memory Stick Pro/Duo with at least 300 MB for the best performance.

Downloads:

(UPDATED) DOSBox Package (REQUIRED!!!):
MediaFire - http://www.mediafire.com/?opcdnldmdw1
SendSpace - http://www.sendspace.com/file/47sbvx
Installation:
1. Download file from link above.
2. Open archive with Zip/RAR utility, like WinRAR or WinZip. Note: The default Windows Zipper does not work with this file, only zip format.
3. Connect your PSP to your computer.
4. Go to the root of your Memory Stick.
5. Now go to the file you’ve downloaded above.
6. Drag the PSP folder to the root of your Memory Stick.
7. Wait for a while then it’s done. But wait, it will not be fun unless you put the Windows img below.

Windows 3.1 IMG (Size: 7MB):
MediaFire - http://www.mediafire.com/?0ngjlexsty2
SendSpace - http://www.sendspace.com/file/73lvx7
Installation:
1. Download file from link above.
2. Open archive with Zip/RAR utility, like WinRAR or WinZip. Note: The default Windows Zipper does not work with this file, only zip format.
3. Connect your PSP to your computer.
4. Go to PSP folder on your PSP.
5. Then go to GAME folder.
6. Then go to DOSBox folder.
7a.For default Windows Zipper: Right click on w31.img in the zip you opened, click copy, then go back to the DOSBox folder, paste it there.
7b.If your using zip utilities like WinRar, drag the w31.img in the zip file you’re opened and in to the DOSBox folder.
8. Wait for a while then it’s done.
NOTE: TO START WINDOWS 3.1, START IT JUST LIKE BEFORE, WHEN YOU GET TO A COMMAND LINE, TYPE IN “WIN” AND PRESS START. THERE! WINDOWS 3.1 IS BACK!

Windows 95 IMG (Size: 44MB):
MediaFire - http://www.mediafire.com/?w9cj2dncoy1
SendSpace - http://www.sendspace.com/file/nw3j6t
Installation:
1. Download file from link above.
2. Open archive with Zip/RAR utility, like WinRAR or WinZip. Note: The default Windows Zipper does not work with this file, only zip format.
3. Connect your PSP to your computer.
4. Go to PSP folder on your PSP.
5. Then go to GAME folder.
6. Then go to DOSBox folder.
7. Drag the w95.img in the rar file you’re opened and in to the DOSBox folder.
8. Wait for a while then it’s done.

Basic Keys Instructions:
Analog Stick: Move the mouse
L Trigger: Left click
R Trigger: Right click
Other keys: Keyboard (instructions below)

Keyboard Instructions:
If you want to see the confusing combo keys, go here: http://www.niwra.nl/psp/p-sprint-c/doc/images/keygroup1qwerty_black.gif
When started this program, you should see Dosbox Menu, Hold Digital-Left and press X, this will go into numeric key mode. Then press Square twice, it’ll get you into Boot Menu. Then here’s the key if you need to boot to certain Windows:
Windows 3.1 - Square, Square
Windows 95 - Square, Triangle
Windows 98 - Triangle, Square
Windows XP - /\,/\

This should do it unless you want to type something (it’s hard to find letters from all keys so don’t really try to do that).

I did NOT make any of these file, just this video to show you that it is possible that you can run old Windows on your PSP. Now you just have fun with these and make your friends jealous.

I AM NOT RESPONSIBLE FOR ANY DAMAGE THIS HAS CAUSED TO YOUR PSP, SO DON’T COME CRYING TO ME SAY “YOUR STUPID FILES BROKE MY PSP!”

If you have any problem or questions feel free to PM me.