well-it failed again with illegal operation:
4/11/2010 4:09:00 AM: Building project step 'File version'...
Error creating custom action 'Run Program': Illegal operation attempted on a registry key that has been marked for deletion.
4/11/2010 4:09:00 AM: Building failure step 'Send Generic Mail-step failure'...
Error creating custom action 'Send Mail': Illegal operation attempted on a registry key that has been marked for deletion.
4/11/2010 4:09:00 AM: Building failure step 'Send Gen Mail-failure of failure step'...
Error creating custom action 'Send Mail': Illegal operation attempted on a registry key that has been marked for deletion.
4/11/2010 4:09:00 AM: Build ended (elapsed = 00:19:12).

any suggestion about what to do next in order to have build working ?

I'm not sure. We have built the build.bld sample continuously for several days on a Windows Server 2008 R2 Datacenter machine (clean install + VBP 7.7, Windows Update disabled, VMware guest) and have not encountered any errors or hangs. There must be something unique about this machine that is a factor somehow. We would need to be able to reproduce the problem to investigate further. Could you try it on a different machine or give us access to the problem machine?

tks for answer ,will speak with managers and let you know how should we do it ...

I prepared a different machine -virtual also -same OS as the first one (W2008Server R2 X64).
The problem appeared again but this time on a different step:
2/12/2010 2:29:33 AM: Building project step 'Create versions.txt'...
2/12/2010 2:29:33 AM: Building project step 'File version'...
Error creating custom action 'Run Program': Illegal operation attempted on a registry key that has been marked for deletion.
2/12/2010 2:29:33 AM: Building failure step 'Send Generic Mail-step failure'...
Error creating custom action 'Send Mail': Illegal operation attempted on a registry key that has been marked for deletion.
2/12/2010 2:29:33 AM: Building failure step 'Send Gen Mail-failure of failure step'...
Error creating custom action 'Send Mail': Illegal operation attempted on a registry key that has been marked for deletion.
2/12/2010 2:29:33 AM: Build ended (elapsed = 00:14:10).

Hello again
I had some other tasks so I put on hold this issue.
Now I decided to install a fresh OS on this virtual machine
This time I used W2003Server R2 SP2 .
I see the errors like "Illegal operation attempted on a reg key ..." are gone.
The only problem is the old one I used to have -from time to time the build remains frozen at a step of "Make VS.Net" type.
I have installed VBP version 7.7
I tried even to uninstall the Antivirus running on this machine but it did not help
Could you please advise what else should I do to have this working ok ?

I'm not sure. We've also tested a lot on Win2003 R2 SP2 and haven't had any hangs. We would need to be able to reproduce the problem in order to investigate further.

I have the same issue on a new build machine.
After some research I found the resolution:

http://blogs.msdn.com/b/distributeds...rver-2008.aspx

Resolution
As a workaround it may be necessary to disable this feature which is the default behavior. The policy setting 'Do not forcefully unload the user registry at user logoff' counters the default behavior of Windows 2008. When enabled, Windows 2008 does not forcefully unload the registry and waits until no other processes are using the user registry before it unloads it.

The policy can be found in the group policy editor (gpedit.msc)
Computer Configuration->Administrative Templates->System-> UserProfiles
Do not forcefully unload the user registry at user logoff

Change the setting from “Not Configured” to “Enabled”, which disables the new User Profile Service feature.