What is csrss.exe process and why does it constantly occupy30MB of I/O

[grofaty]

Hi,
I have installed free Microsoft small program Process Explorer from web page:

http://www.microsoft.com/technet/sysinternals/ProcessesAndThreads/ProcessExplorer.mspx

From View | Select Columns | Process Performance tab I have selected I/O Delta Total Bytes.

I have found out that process c:\windows\system32\crss.exe is constantly occupying 30 MB of "I/O Delta Total Bytes" on Windows 2003 SP1 computer and there are no process that would occupy CPU (CPU is less then 1% utilized).

At the same time I have tested the Process Explorer program on my Windows XP SP2 desktop computer and there was no program running, the result: I/O Delta Total Bytes was 0!

Now I am wondering what is csrss.exe process on Windows 2003 and why does it occupy a 30 MB of I/O when no other program is running?

Thanks,
Grofaty

 

[itsp1965]

To quote MS:
This is the user-mode portion of the Win32 subsystem (with Win32.sys being the kernel-mode portion). Csrss stands for client/server run-time subsystem and is an essential subsystem that must be running at all times. Csrss is responsible for console windows, creating and/or deleting threads, and some parts of the 16-bit virtual MS-DOS environment.

Don't know what an I/O Delta Byte is but it is not uncommon for this process to use up memory (do a lookup on CSRSS.EXE in the MS knowledge base for various articles on it).

 

[grofaty]

Hi,
thanks a lot. I know csrss.exe is a Windows program that must not be deleted, but why does it occupy so much of disk I/Os on Windows 2003 computer (I/O Delta Byte is disk measure) when no other program is working? Comparing to my Windows XP desktop which doesn't use any disk I/Os when it is idle.
Thanks,
Grofaty