I need to change from DOS mode to windows, i opened up some file which opened a DOS command prompt, now everything i open, opens in Notepad with code that never ends.

You need to change what program Windows associates with that type of extension. It sounds like the file type you are trying to open is associated with notepad.exe. You'll need to change that to the program that can read that type of file.

If it's XP you are using, here's the info from Microsoft.
How to change or select which program starts when you double-click a file in Windows XP

i honestly think its more than that cuz i have tried that my brother said the next best thing to do is reformat and or repartition.

What type of file are you trying to open, what is the extension? (.jpg, .doc)

everything from windows media player to video games or ventrilo. everything i open opens with notepad, wen i reboot all my exes open in notepad, not system ones but user ones that i have start up on startup

If you have system restore turned on, you should be able to go back to when it was working properly. That is probably the safest fix.

There are several websites that offer a fix for this.
exe opens in notepad - Google Search

.EXE files always open with Notepad or any other application ?
Broken EXE Association

yea ino i tried that and it opned in notepad too lol, idk wat to do.

i tried actually the exefix_xp it worked perfectly
tysomuch

Anytime.
Thanks for posting the fix that worked for you. It will help others I'm sure.