I’ve been playing Enemy Territory for a while, with no problems. Recently, my computer crashed, and we had to install Windows XP (I was playing on Windows 98 and 2000 Pro). Now, my game is lagging to the point where I can not play on any of my regular servers. What can I do to fix this?
Enemy Territory Problem
Make sure you got mobo drivers installed and the correct drivers for your vid card would be a start.
Also post your system specs as this will enable people to help you better.
Also post your internet connection speed 
You’ve probably got a cruddy computer. If you decrease your graphics settings you can get a better performance. Try putting the screen size lower etc
one thing that will definatly help your game performance is /r_picmip 3 then /vid_restart…check it out =)
I just tried a few things my friends suggested, to no avail. Here are my computer’s specs:
Windows XP
2 GHz AMD Processor
512MB RAM
ATI RADEON 9600 video card
Over 100 gigs of free hard drive space
Cable Modem
The game never slowed down before I installed Windows XP. I could crank up the graphics and run smoothly before, now even on the lowest settings I lag terribly. What can I do?
Update punkbuster manually using pbweb.
There is also a problem with punkbuster and XP, you must run ET with admin privilegs.