Cleaning system Files

My system is infected within some major system files. Here is the list:

C:\windows\repair\updatr.exe
C:\windows\system32\service.exe
C:\windows\system32\svcvhost.exe
C:\windows\system32\svhost.exe
C:\windows\system32\tskman.exe

How can I clean these without further damage to my already fragile system? Thank you in advance for all the help.

Digital Comfort

Scan and send files to Chest instead of deleting them.

For further cleaning, I suggest you scan your system with antispywares and antitrojans applications (download, install, update and run them):
Ad-Aware
Spybot Search and Destroy
A-squared
Ewido