You're starting/stopping services on the remote machine, but removing keys and directories on the local machine. The RD and DelValue commands should look like this:

 Code:
RD "\\"+$strComputer+"\c$\Program Files\Common Files\Symantec Shared\VirusDefs\" /s

DelValue("\\"+$strComputer+"\HKLM\SOFTWARE\Symantec\SharedDefs ", "SRTSP")

...unless I'm misunderstanding what you're trying to do.