AVRT.DLL corrupt or missing

Vista x64 premium. It shut down while playing music and would not reboot.
I did a repair from the vista disc.
There is no sound and a message about a corrupt or missing

AVRT.DLL

Anyone know how to repair this file?
Thanks

Go Start>Run ("Start Search" in Vista), type in:
sfc /scannow
Click OK (hit Enter in Vista).
Have Windows CD/DVD handy.
If System File Checker (sfc) will find any errors, it may ask you for the CD/DVD.
If sfc won't find any errors in Windows XP, it'll simply quit, without any message.
In Vista you will receive the following message: "Windows resource protection did not find any integrity violations".

That does not work it comes up with a few messages then nothing

Go Start>Run ("Start Search" in Vista), type in:
sfc /scannow
Hold CTRL, and SHIFT, hit Enter.

You can download that file here:

http://www.dll-files-download.com/A/...1-12/1137.html

It normally lives in System32.

I gave up and reinstalled vista. My question now is how did this file become corrupt.

There is no answer to your question. Things like this just happen.

Indeed. There are a myriad of causes, but a not uncommon one is for cosmic rays passing through the RAM chips to cause a bit flip. Sometimes that corrupt data gets written back to the hard drive.

Actually, given that all it needs sometimes is for a single bit to get flipped to cause disaster, I find it pretty miraculous that it happens so rarely :)

Had the same problem, avrt.dll was corrupt and causing an error with logonui.exe. Sound wouldn't work at all.

I copied avrt.dll from my other computer.
On corrupted computer, find avrt.dll in your windows/system/32 folder:
1) right click, properties, and change the owner to yourself
2) once ownership is set you will be able to change permissions
3) give yourself full permissions
Copy the new avrt.dll into your system32 folder

Restart, profit

you might need to disable user access control first, you can do this under control panel > users