Attempted to install windows Defender on 4 Dell desktop PCs.

1 was reformatted with WinXP pro, windows defender installed fine.

the other 3 stopped during the installation stating I was not authorized to start the required service.

I tried this logged in as a user with adminstrator rights and as the local adminstrator on the workstation, still recieved the same error.

Tried microsoft tips found here : http://support.microsoft.com/?kbid=555175

still no help.

Any other ideas? Appreciate any help!