corrupt mfc42u.dll

Hello,

I need help after a series of problems. System: Vista Home Premium.
First thing that happened, is that my wifi did not work anymore. I had a look and it said the driver would be out of date. I was not connected to the internet, so I could do nothing about it.
Then, I rebooted the other day and had the User service service failure. I did a system recovery and could log on again.
But now I have the problems, that the mfc42u.dll is corrupt and many windows programs do not run anymore. What to do?

I already run the sfc in safe mod as admin. Says it found a corrupt file, but cannot repair. in the cbs log it says, the file in store is also corrupted.
Cannot do any earlier system recovery point, because there is none
I ran checkdisk...could not find any problems

I do not want to install vista new.

Thanks for your help