Windows Xp will not startup

Hello,
Hi

I have a HP Pavillion dv1000 laptop and have Windows Xp. It has been working relatively fine(except the fact that it overheats sometimes but then I usually shutdown my computer either by going to the start menu and following the procedure of shutting down the computer or I will put my computer on standby or I will just directly press the power button on my laptop and then it will be cooled down and works fine). My problem is that on Saturday I was using my laptop, running the internet and some microsoft word documents. Well I wanted to close some word documents however they wouldn't close(usually if upon closing a document or my internet browser sometimes my computer will freeze and will open a new window saying that ''this program is not responding would you like to end now'' and I would press end now and then after a few minutes the program(s) would close and everything would work fine. However they wouldn't close on Saturday and my windows task manager wouldn't open when I tried(and it alwayss works). So I put my computer in stand by( the Word documents that could not be closed were still open and my internet browser was still open when I put my laptop into standby). But...instead of going into standby my computer's fans began making a rushing sound like as if they were working too much or overheating(sorry about the vocab I am not very good at computers). So I decided to shutdown my computer by holding down the power button and the computer closed. Then after 2 hours or so I press the power button to restart my computer and I got the regular windows xp loading screen buttttt then all I see is a blank blue wallpaper without any desktop items or start menu or anything! I only have a blue blank wallpaper and my mouse cursor. Please if anyone knows anything please help me

P.S. If anyone knows a way to fix this problem without having to reformat the whole computer(because I have important files that I can not afford to lose) that would be much appreciated!

Thanks