I've recently implemented SUS on my network and have one computer who can't grab updates because the BITS service won't start. When I attempt to manually start it I receive Event ID 7024 that says BITS terminated with service-specific error 2147942405 (0x80070005).

The only thing I've been able to find has to do with Terminal Services being disabled, but that is not the case here.

Contributed By: Edward Reus [MSFT]
Here are some things you can try:

1. Is it possible that the BITS service is not being run under the LocalSystem account? If you go to the "Administrative Tools -> Services" dialog, check to see that the BITS service is configured to run as LocalSystem. If the service is not running as LocalSystem, then it may not have access to the service's state files. For this reason and others, this service must be run at LocalSystem.
    

2. Another possibility is that the state files (or the directory they are in) is not accessible from the Service, for example if the security on these is set such that LocalSystem doesn't have access to open the state files.

You can find the state files in the directory "%ALLUSERSPROFILE%\Application Data\Microsoft\Network\downloader\". The two state files are "qmgr0.dat" and "qmgr1.dat". Note, for example that the Network or downloader directories may exist but not be accessible to LocalSystem account.

Also check to see if the BITS service is being run under the LocalSystem account.

We may need to look at the log files to try to see why the service isn't starting. You can enable BITS logging with the following commands:

set BitsKey=HKLM\Software\Microsoft\Windows\CurrentVersion\BITS
reg add %BitsKey% /v LogFileFlags /t REG_DWORD /d 0xfbcf /f
reg add %BitsKey% /v LogFileSize /t REG_DWORD /d 20 /f

These two registry values enable full BITS logging and sets the log file to a circular log file of 20MB in size. The BITS service will then need to be restarted (if by some reason it is running):

net stop bits
net start bits

Each time BITS is run (from service startup to service shutdown) will create a separate log file. When it is started, it creates the log file "%windir%\system32\bits.log". If a previous log file exists, it is saved (renamed) to "%windir%\system32\bits.bak"

The Downloader directory is created by BITS and should have full access for the Administrators group and also full access for SYSTEM (Local System internal account). You should be able to browse to the Network directory and check the properties of the Downloader directory by right-clicking on the folder for Properties; check the "Security" Tab and make sure that both "Administrators" and "SYSTEM" have all of the "Allow" properties selected (except for "Special Permissions"). None of the "Deny" options should be selected.

Then check the Security Properties for each of the qmgr0.dat and qmgr1.dat files. These should also have full access for both Administrators and SYSTEM just as with the Downloader directory.

Try deleting the "downloader\" directory and "qmgr0.dat" and "qmgr1.dat" files and see if they are recreated. BTW, Don't delete the "network\" directory.

In this case deleting the "downloader\" directory did the trick - the BITS service starts now.