how to install Windows XP (SP1) with pre-installed Windows vista

I bought a new Compaq desktop (SR5152NX) with pre-installed Windows Vista (Hoem premium edition). the hard disk is 250 GB sATA disk. I was trying to install windows XP (SP1) into this computer so I can use the multi-booting function. I read some postings from this forum and followed the suggestions from the postings. (for esample, create a new partition in the same hard disk.) However, I have experienced some issues during the Windows XP (SP1) installation. I hope someone can give me a help to solve my problems.
Question 1). Windows XP did not automatically restart when the screen said XP will automatically re-start in 15 seconds. (I re-started the computer after I waited for 30 minutes.)
Question 2). follow the question 1). After i re-started the computer, XP was working fine and then froze at the point of 34 minutes left to complete the installation. I repeated the several times from beginning and it always froze at the same point. I was wondering whether someone can tell me what happen to my computer. What should I do to fix this problem?

Thank you in advance for your help.

JP