Client/Server Run-time Services - CSRSS.EXE
Csrss.exe is a service that installs as part of your Windows opearting system. It's a critical part of the Win32 subsystem and is responsible for console windows, creating and/or deleting threads and some parts of the 16-bit virtual MS-DOS environment.
A description of services that run under svchost in Windows XP can be found at http://support.microsoft.com/default.aspx?scid=kb;en-us;314056.
A description of default services running under Winodws can be found at http://support.microsoft.com/default.aspx?scid=kb;en-us;Q250320.
Some computer viruses can infect or overwrite this file. These include W32.Netsky.AB@mm worm, the W32.Webus Trojan, and the Win32.Ladex.a worm. If you think you have a virus, we'd recommend a full system scan with an up to date antivirus program.
Service
Microsoft