Windows 7 backup failure

[realaleman]

Ever since I installed Windows 7 on my desktop PC I've been using the backup program in the control panel to backup my C: drive to an external 1Tb drive. This seemed to be quite good to have backup and restore built in. However, just recently the backup has failed with the message "Windows backup did not complete successfully" and a further dialog says "The process cannot access the file because it is being used by another process".
Error code 0x80070020

What has gone wrong? I have about 350Gb free on the external drive so that should be ok, and I'm not aware of running any program in the background which is accessing any file.

Help!

[VHG]

Basically another program is "holding" a file that Windows backup wants to backup.

Hard to say what that program it is so make sure you stop all programs that are running.

Try it at another time to see if it works then.

A search in Google on 0x80070020 may give some solutions.

Here is one I found

http://social.technet...79c-a10e-ff45aba28d82

[realaleman]

Thanks VHG. It seems from your link that a number of people are getting the same problem as me. I just find it strange that backup used to complete OK and now just will not, whatever I do. I am not actually running any other programs, so there must be something running automatically when I boot up. How do I find out what programs are starting up?

Thanks...Geoff.

[Davethedog]

http://support.microsoft.com/kb/883825

It appears to be an update error.

[realaleman]

Ah! I've just found it. About that time I changed my anti-virus from AVG to Avast.
Removing avast and going back to AVG seems to have cured it. Avast must be continually opening files when the backup is taking place.