Hmm
1. ask him to try a reinstall
2. Does he have any hacks or
**** like that in his wc3 folder?
3. could be ram, I'm guessing that there is more than build etc. try to get the entire thing plz.
4. get him to run antivirus and see if anything pops up
The only "solution" that I could find was the case where a guy kept uninstalling and re-installing 2 to 3 times. He claimed success, whether it works or not idk.
best of luck baitens :/