Service Pack 2? You need to seriously update your computer.
Windows Update should be visible from your start menu, if not look around. OR update.microsoft.com
Make sure your system is clean - run some kind of virus scan (MS Security essentials is free) & run some kind of malware app like Malwarebytes, it does have a free version also. (
www.malwarebytes.org)
You can't multi-box on p99, so if you have EQ open on this other PC and are trying to use it on this PC it won't work. Also, did you make the change to the eqhosts.txt file?