Trustedinstaller.exe missing

[alcapwn1010]

As the title says, i'm working on a computer for someone and apparently trustedinstaller is no longer on the computer anywhere, i tried searching for it manually, and i tried using command prompt. I can't run the System file checker, it says "windows resource protection could not start the repair service" I also cannot manually start the trustedinstaller, it gives system error 2 "the system cannot find the file specified"

 

I have no idea how to fix this without upgrading to a new version of windows, which i want to avoid doing if at all possible, the computer has a lot of software and data that i need to keep, and some of the software doesnt play nicely with anything past windows 7. 

[Mug]

Is there no way that you can just roll back?

 

That's what I used ot do when I did this. Do 10 mins of work and charge £50 for it

 

$$$$$$$$$$$$$$

[alcapwn1010]

No, unfortunately backup was never setup, and I don't know for how long its been like this, so chances are even if I had a backup it wouldn't go far enough.