1. You will need to format that drive, or put it on a new partition. Installing it on the same partition will corrupt XP.
2. Yes, but only two speakers.
3. AVG and Avast, AVG has active scanning, Avast doesn't. Chose by personal preference.
4. Use google for the programs, but they should all work. Some may need to be ran in XP SP2 mode.
5. Not sure what you mean. Firefox works with Vista though.
Cisco CCNA, Comptia A+, 1/3 through CCNP