Instruction at "0x76c91645" referenced memory at "0x00000014". The memory could not be "read". What does this mean? I keep getting this error upon boot. My computer is also running extreamly sluggish (5 mins to open a folder). Any help would be greatly appreciated.

We're gonna need more info about your system, including the OS version and your A/V and anti-spyware apps. This sounds like a serious security issue off-hand...

It's acually a friends a comp. I know he is running WXP and Norton Anti-virus. What is A/V?

That's all I know off hand about his computer atm.

A/V is anti-virus software. Does he have it fully updated? Posting a Hijack This! log would help (in the security section of the forums) and more hardware info is needed. Like I said, it sounds like it might be a security issue, but it could very well be an overheating issue or a Windows problem or even a heavily fragmented hard drive. We can't tell for certain yet.

referenced memory at "0x00000014"

This sounds a lot more like a memory issue to me, 0x00000014 is a memory address, the other number I think is a CPU instruction reference number. I can't find anything on the exact error message, but if I understand it right, it means the computer can't read that section of memory. Each physical section of memory is given a numerical address, since numbers are all the computer ever sees or "knows". When a chip on your memory stick goes bad for whatever reason, that error message is to tell you which chip is inaccessible. Which chip I don't know, but I'm pretty sure from that error message it's a memory problem.

Swap it for known good memory or run a memory tester and see what it comes up with. I think Memtest86 (http://www.memtest.org/) is the one most commonly recommended around here...