I can't create a homegroup after repair install

Hey, I came across an issue (too good to be good huh?). The thing is that after the upgrade I can't create a homegroup, the Peer Networking Grouping, the Peer Name Resolution Protocol and the PNRP Machine Name Publication Service refuse to start.

I already tried the known solution of deleting the idstore.sst file from the C:\windows\serviceProfiles\LocalService\AppData\Roaming\PeerNetworking folder but that didn't worked at all.

I really don't want to resource to formatting, I'm sure there has to be a solution somewhere since so far is the only thing I'm having issues with now.

Do you have any suggestions on what I can do?

Thanks in advance.

I included a REG file that will modify the registry for your problem.

I am not saying that it will fix the problem but its a "try"

I need you to do a BACK UP of the reg first before importing this REG change first.

Registry - Backup and Restore

When you do a registry change.. it is always good to be in admin account and when you do it, reboot the computer for the new change to happen.

Maybe i should have Work Cited the page... my english teacher would have gave me a zero if i didn't....

my school sucks!

Thanks for the help but that didn't worked. I did also the tcpip6 registry thing which indeed that key was missing but not that it did much anyways.

There has to be something else. When I try to start the Peer Name Resolution Protocol I get the error code 0x80630203 And the event viewer shows something about that the cloud could not be created. But so far I came out empty about other solutions

Here is the error text from the Event Viewer:

The Peer Name Resolution Protocol cloud did not start because the creation of the default identity failed with error code: 0x80630203

The problem is the creation of the identity for what I'm seeing, so I'm sure something is keeping it from being created, what is it? I really don't know

Also the C:\Windows\ServiceProfiles\LocalService\AppData\Roaming\PeerNetworking folder is empty, I deleted everything from it but didn't fixed anything since Windows didn't re-created it's content.

I know this is late, but just experienced the issue myself, after restoring a windows 7 system image.
Use the Vista instructions here for changing security: http://social.msdn.microsoft.com/Forums/en/peertopeer/thread/f195c462-9417-4779-9fca-583ca3fe06f0
but the directories for Windows 7:
where USERNAME is your windows 7 login name, USERSID will become apparent when you get to the directory
C:\Users\USERNAME\AppData\Roaming\Microsoft\Crypto\RSA\USERSID give the USERNAME Full Control
C:\ProgramData\RSA\MachineKeys give Everyone Read/Write (I went ahead and granted full control on my machine)
Then run the services (pnrpsvc and p2pimsvc), run the Homegroup troubleshooter and let it fix whatever problems it finds.
Good luck!