Hi this is my first post so please be gentle with me.

My problem is when i move my mouse my Csrss.exe file takes up 75% of my cpu time.

it has only just started doing it, and nothing new has been installed.

Im running and AMD 4800 cpu
Asus a8n MB
2gb corsair ram
2x 7800gt Nvidia cards

it has been running fine for 2 years

any help would be fabulous.

Hey and welcome to PCHF

I don't know if you know this or not, but Csrss.exe is the main executable for the Microsoft Client/Server Runtime Server Subsystem. Apparently, it can also be a virus and this would suggest why it is taking up so much processing power.
Try running your anti virus program to see if that will pick it up, when i had a similar problem to this my antivirus software didn't pick it up so what i did was:
Click Start
Click Search
Clikc All Files and folders
Enter Csrss.exe
Click search

The correct file should be in C:\Windows\System32. Anywhere else then i would presume you have found your virus!

What you have to do then is delete it and remove it from the bootup. I couldn't delete mine when i had it so i had to do it through linux, i am sure there is a way to do it within Windows, maybe somebody could give a set of instructions for that??

Hope this helps

Edit: You might want to run HiJackThis and post the logs it creates on the "HiJackThis Logs" Forum the security experts will take a look at it and give you far better advice than me

You can download HiJackThis here.

Thanks for the advice.

i have posted my log.

the problems all started when pc crashed halfway through Windows update, i think my file may be corrupted. it seems to fix itself until i rebooted then started again.

in that case, try running the update again

I have rerun the update no effect.

run 3 antivirus scans all clear

hijack this log got a clean bill of health.

its making using anything impossible as it just freezes as soon as the mouse moves.

Just to rule out the possibility of malicious software then when it 'hoggs' the CPU go into the task manager and select processes, click on image name until you see csrss.exe. If there is only one and it is taking the CPU then it is another problem (By the way, Csrss.exe should be a SYSTEM process).

Is your computer connected to a Network?

Thanks for the help I have managed to resolve the problem now.

It turned out to be a corrupted mouse driver in the Logitec mouse. got rid of the all singing all dancing we can do anything driver and just reinstalled the basic one. now everything is running fine.

thanks again