Although a number of discussions refer to "Microsoft Commando Defender" as malware, it appears like there may be legitimate reasons for it being on the computer. Is the computer you're using a "rental" or "company" computer? If so, then please see the last post in the link below. It refers to a program which installs Commando to prevent renters from installing programs of their choice.:

http://answers.microsoft.com/en-us/windows/forum/windows_vista-security/infected-with-microsoft-commando/60d0706d-cfcf-484e-a797-e957a0a93fa3

If this is the case, then you may have few options.. Either return it to the company from which you received it, or wipe the drive and reformat the machine.

Hope this helps.

Grif