Having a spot of bother with one of our presentation servers, when even a single user logs in the CPU usage spikes to 100% and stays there until all users are logged off the server. Looking in task manager the process/processes using the cpu time are always different. The performance of this server is understandably pretty awful because of this. We also have a second presentation server, specced identically with exactly the same software installed on it which doesn't have this problem.

I've tried using the CPU optimization option in Citrix, this crippled the server and made it unusable in that everyones sessions froze

I've also tried using ThreadMaster which hasn't helped matters.

Does anyone have any suggestions?