Hi, and Windows XP questions

Hi, Im Colin. I just got an old Dell Inspiron 7500 laptop from my parents. I have been having some problems with it. It is currently running windows XP. Everything loads fine, I can log in, and get to my desktop. After about 30 minutes of use it will go to stand by and when I try to come back from it, it crashes ( I think ), either way it doesnt come back on without restarting it. My dad was having the same problems and that was the reason it was passed down to me. I don't want to get rid of it because besides the fact that it crashes, it runs fine for what I want it to do. How can I get it to stop crashing, is there a factory reset? Any help is appreciated and I am very much new to this so if it could be explained for noobs, it would help alot.
Thanks