I'm without a computer

Just as I was getting some free time to blog about all I have been doing, my computer breaks. On Tuesday while I went into a different room Little Man climbed up and thought he would play his Thomas the Tank computer game which he loves.. ONLY he didn't ask and didn't know what he was doing and when I came out I saw him moving the mouse and clicking everything in sight and just as I went to get him off the computer it shut down on its own.
I went and restarted it ONLY it gets so far and then tells me Windows something or other has either been removed or is corrupt and I can try to fix it with the window disc.. ONLY I don't have that disc. It is at my parents house(we think it was there computer before it was mine) We tried yesterday to uses my Grandpa windows 2000 disc but the computer kept shutting down and restarting with the same message
I don't know if I will be able to fix this one or not..
I'm using my grandparents computer to type this post
I just wanted to let you all know why I"m MIA and I don't know how long I'll be without a computer. Either till we fix the problem or save up the money for a new computer I guess. UGH.. I'm not liking this at all.