First of all, is a NON LUNARPAGES issue. Im tinkering with a Windows based webserver here at home (Don't worry LP, im not divoring you

The web server software can be found here:
http://www.aprelium.com/ , but that is irrelevent, I THINK.
First of all, here at my stats:
2 gigs of ram
2 gig processor
Windows XP
a basic SATA hard drive
Now the problem. Sometimes when i have a few people downloading from my box they claim that the file download dialog box sometimes takes UP TO 45-60 sec. before it pops up. Im trying to pin point what causes this.
So what would cause this delay when i have a few people downloading large files?
This is what I've heard so far:
I/O speed could be the issue (aka slow hard drive)
or
Need to defrag.
Any other ideas?
thanks guys.