Installing new Os (Xp Pro SP 3) over 64 bit Xp pro

I have been trying to install a new version of XP on my computer mainly because I can't handle 64 bit and it's refusal to be compatible with my wireless card. First of all, I do not have a registered version of the 64 bit due to no internet connection which didn't allow me to register my copy and in turn locking my computer unil I do so. My friend gve me a copy of XP pro SP3 and I want to install it, but I have a few issues. How do I delete the old OS? How do I install the new one? I have been having some problems with opening the bios and what not, I am using ASUS P5N73-AM mobo. I really need help with this, because it is limiting my use of the computer, a brand new computer which I have not been able to consistently use since the time I bought it.

I have a legal cd, but i can't boot from cd

came here for help not to be interrogated, and my friend had bought that copy from tigerdirect.ca, thank you Grumpy but I have solved the problem

actually it was a display problem, so you didn't answer my question at all, so next time when you feel like being an ass, don't post on my thread

I was not able to acess BIOS to delete and install windows xp. Nothing was wrong with the cd, it worked like a charm, so once I fixed my display I was able to access Bios and do whatever I needed to do.

Simply you were wrong, post over