Quote Originally Posted by AmunRa
Its zonealarm that causes it, even if you turn it off, it will still do it. The only solution is to unstall zonealarm completely, then install. Worked for me, should work for you too!

P.S.
According to activision, zonealarm has been a major problem for installing their software
- I know this has been dormant for a while but I just wanted to say thanks; I had exactly the same problem (endless _isC**.tmp errors) trying to install C&C Generals/Zero Hour, it was driving me nuts and I hadn't a clue what to try until I came across this thread.
It was uninstalling ZA that completely fixed the problem.

I hope you see this and I can pass on my thanks.

Thanks a million.