whenever I try to instal worms 4 mayhem
an error pops up before the instal wizard will start:
http://img259.imageshack.us/img259/918/errormj2.png
Any ideas?

Please post your system specs!

We can't help if we don't know what your system is.

I'm sure we'll be able to find a solution. There's loads of good ideas here.

I know this may sound daft, but have you tried following all the recommendations on that error message?

you have a defective game
get a new copy
:p