XP wont boot up

Help. I have been asked to fix my BF's bosses comp. He cant boot up xp. when i turn the comp on it goes thru bios and then to the windows screen for a minute then i get a blue screen of death for just a second. too fast to see what the codes are. then it goes back to bios and starts all over. it just stays in this continuous loop. can this be fixed?

1) You might want to start by backup up his files. See How to recover your folders/files when Windows won’t boot

2) You can try rebooting after chkdsk /r (from step above). That will also sometimes work

3) Otherwise also see 10 things you can do when Windows XP won't boot (http://articles.techrepublic.com.com/5100-10878_11-6031733.html)