Broken Digital Signature

Hi, I would like to know if the above is harmfull or dangarous, issued by Microsoft, the message reads : Discription :

c:\Doucuments and Settings\Mercury\Local Settings\Temp\{B35E8D6F-AODC-4AF2-830F845962DD3EA}\{757AD3D4-036B-42FA-BOA4-96BD6F4605AO}\40comupd.exe ".

This shows when I do a scan, in fact with all scans, using the AVG Antivirus 2013 version. It shows up as :
result 'STATE Infected' ,
Type ' File or Directory',
Severity 'Message'.

Can this be removed or repaired
Never had this problem with previous versions. Any help? Thanks
Rusty