Depending on where this csrss.exe (Client/Server Runtime Subsystem) is trying to load from will determine if it’s supposed to be running or not. If its loading from C:\Windows\System32 then its most likely supposed to be starting but if its loading from somewhere else then it can be a spyware or virus application trying to load with your computer.
One way to check this is to MSconfig and see if its listed there and then look in the Command and Location columns and see if you can tell the path to where its trying to run from. You can uncheck it so it doesn't start up with your computer next time but many times it will find its way back to your startup again.
Then I would do some spyware and virus scans in Safe Mode and see if you can clean it from your system.