If you want to monitor temps, try speedfan.

It's not a crappy case if your temps are that good.

Sounds like a harddrive is dead

You might want to read this

http://www.pcworld.com/article/154912/vista_sp2_six_things_you_need_to_know.html

It will work.Just make sure you put in as much memory as you can.I use to sell old suplus puters,and xp went on all of them.They ran just fine,pending they had at least 512 of memory.

Are you running a sever motherboard?Or is that a hyperthearding cpu(which shows up as 2 cpu's but is really 1)To get the most out of that card you need a duel core and 2 gigs or ram.It sounds like cpu bottleneck to me.I havre the sapphire version of the card,and it shreds games.

Rest of your specs?

It's VGA

You have enough ram and cpu speed to push the 3850,not sure about the psu.You can try it,but if it doesn't work,don't give up,try to use 2 rails(it comes with a power adapter)that are as free as can be.You will be happy if the card runs,I love mine,and it benchs about the same as an 8800GT.If you run into problems,shoot me a message.I will help if I can.I did a lot of research on this card before I bought it.