WSUS Service fails to start with error 193, WSUS Service is not a valid Win32 application

[ell]

I'm having trouble updating a win 8.1 machine, WSUS offline can't complete, keep getting
WSUS Service fails to install each update with Error 193 / %1 not a valid Win32 application on each update, anybody seen this?

 

[nlinecomputers]

No, but logically from the error, you are getting you must have some kind of corruption going on. Time to check things with chkdsk, SFC, and DSIM.