Windows Backup fails - Access is Denied

Possible Duplicate:
Windows 7 Backup Fails

Possible duplicate of Windows 7 Backup Fails

I use inbuilt Windows 7 backup functionality to create and store system image on my network store. Until recently it worked like a charm.

Each time I press "Back up now", it immediately fails with "Access is denied." message. Error code is 0x80070005. Absolutely no additional info. I don't know what access is denied. So I've googled for several hours, read through dozens of forums, and nothing.

What is probably important is that the "Access is denied." error is reported even when the network share is not accessible, so it seems the problem starts even before any actual transfer is done.

Please, tell me if you have any idea what else to try (besides completely reinstalling the system).

What I have tried:

• I went through Event Log (nothing reported besides the message and code already mentioned)
• Recreating the backup job several times
• Completely purge backup settings from registry and recreate it again
• Restoring filesystem junctions
• Restarting services (and checking the services are running)
• Uninstalling new software
• Disabling antivirus
• Checking harddisk with several different antivirus for possible malware infection
• Checking harddisk for errors (including SFC /scannow)
• Recreating the network share, ensuring that correct permissions are set

but nothing works.

Microsoft Answers had an answer to this question.

I pasted it, exactly the way I found it below. (If It works, I'll reformat)

"I went into control panel,administrative tools,services Look for Block Level Backup Engine Service and right click Select properties then logon tab Change from local system to "this account"...browse for your username enter your password...click apply...then ok"