Trying to eek out every last drop of performance on your Windows server? Chopping things down from the registry is a great place to start. Leveraging this on Citrix Servers could improve performance (certainly won’t hurt).
Disable random driver verification
The driver verifier at random intervals verifies drivers for debugging. Disabling this functionality might improve system performance. For many high-throughput systems, every CPU cycle counts. Disable random driver verification with the following registry entry:
Data Type: REG_DWORD
Range: 0 – 1
Default value: 0
Recommended value: 1
Value exists by default? No, needs to be added.
This and others can be found here : Registry Settings that can be Modified to Improve Operating System Performance