unity uninstalling/deleting itself.

when i tried to open unity it suddenly said that the program that i was referring to (via shortcut) didn't exist. as it seems with uninstalling itself, it also deletes its libfxsdk.dll, FreeImage.dll,umbraoptimizer64, libcef.dll . or at least it says that it couldn't find them (when i put in unity program file in it and try to open it it said all of above was missing). it says that i should reinstall the program but it isn't first time that this happened to me. reinstalling does help, but as i said, it is annoying to do many times. any idea what the problem is? i also found other questions similar but none answered.