How can I stop this message appearing?

Hi, I have an Eee PC notebook and everytime I reboot my computer it automatically comes up with these same 2 messages. First it opens a message saying:

'Windows cannot find 'C:\DOCUME~\Miriam\LOCALS~1\Temp\csrss.exe'. Make sure you typed the name correctly and then try again. To search for a file, click the Start button, and then click search.'

So I click OK and then it comes up with this second message:

Could not load or run 'C:\DOCUME~\Miriam\LOCALS~1\Temp\csrss.exe' specified in the registry. Make sure the file exists on your computer or remove the referance to it in the registry'.

Then I click OK to this message and it goes away and I am free to use my computer normally. I'm just worried I might have a virus.
I have ran some scans (spybot, adaware, avg, malware) and they haven't resolved the issue. I also searched for the file using Search but when I tried to delete it, it said access was denied.
Sorry for the long post but I was wondering if anyone could help me out?
Thanks.