rundll32.exe, under normal circumstances, is usually fairly stable. But, over time, files within the operating system will become damaged or corrupted through normal use. Basically, it’s just “wear and tear”, the more you use the system, the more the system has to work, and the more likely the system will have problems. What you could do is make a backup copy of the file(s) before they get corrupted, then, when it happens, you have a good copy of it.
The same thing happened to my PC at home.Do you have internet Access, or are you on a server. If so you probably have a virus on it. Get yourself an updated virus scan and try that first. If no virues found try to reinstall the operating system.
Goodluck