I've looked at other recommended solutions but the problem keeps coming back on this one machine. I've uninstalled 4.2.4, rebooted, deleted the eset directory in program files. Re-installed using a cfg.xml file. System runs fine for a while, updates ok. But after a couple hours the system fails to update with general compiler error. Plenty of free disk space on the drive. Clearing the cache does not fix the problem. User is on a domain and is a local admin on their machine.