operating system seems to be messed up

[coolbz]

When I try to log into windows I  get a error message that says that user profile cannot be loaded, I cannot even do a system restore the message is cannot find C;Window\system 32\rstui.exe Iamnot even able to download or update programs cause the system cannot find the specified path

[Geek-9pm]

How old is your PC or laptop?
Has there been any important changes recently?
New hardware? New software?
Do you scan for  any malware from time to  time?
Do you have another PC that works good?