[Xarslik]

I made a post about this a few days ago, copied for your convienance:

If you're attempting to run EQ on the same machine you're running the server, this might help (needs Win2K or XP and EQW):

Run EQ.
CTRL+ALT+DELETE and go into the task manager.
Look for EQGAME.EXE, rightclick, go Priority->BelowNormal.
Look for WORLD.EXE, rightclick, go Priority->AboveNormal or High.
Look for each instance of ZONE.EXE, rightclick, go Priority->AboveNormal or High.

If EQ lags TOO much, you can try setting its priority back to normal, however leave the world\zone processes running at a higher priority.

This helps a TON when I'm running a server and EQ on the same machine, since DirectX tries to use all possible system resources when running, and the emu ends up lagging\disconnecting a lot.