I left my computer on last night as usual and when I woke up this morning it was turned off. I tried turning it back on but it was only displaying the first page that is usually displayed at the very start and then it turns black. I open the menu where you choose safe mode menu pressing F8 and try opening it in safe mode but it takes an incredible amount of time to load and ends up by restarting at the windows XP loading page. It basically does nothing. I tried restarting it multiple times starting it normally, last configuration etc.. and it always does the same thing and now i don't even have to press F8 to open the menu that gives you the option of safe mode, it always opens automatically. I was thinking of reinstalling windows but i don't want to lose all of my application files and such.
Any help would be appreciated.
Thanks.

Welcome to PCHF
Does it give any error beeps?Is the harddrive functional? is the motherboard functional?Test the harddrive on a second pc if possible.

not really error beeps, I will try the hard drive into another computer but does it matter if my hard drive is from a Pentium 4 and i use it into a intel Celeron?

No, a harddrive is universal, you can connect it on every PC. You just have to look what kind of connection you need for your HD, most common are SATA (standard in every pc you buy today) and IDE (getting replaced by SATA but still very common)...

Robin

Have you tried changing the first boot sequence in the bios to cdrom and booting off the XP disk.
After it looks for and finds your original operating system if will ask if you want to install a new version of XP on that partition or repair the existing one, choose repair.
Change the first boot sequence back to the hdd when done.

I'v removed the HD from the Celeron and tried the harddrive from my P4 into it as the primary hard drive and it does the exact same thing. Then, I tried it as the secondary HD and the Celeron HD as the primary one and windows opened normally and i could view my files of course.