Can't join homegroup

I have 3 computers on my network running Windows 7.

I created a homegroup on one, and successfully connected to it from another.

On the third computer, however, I'm having some problems. If I try to join the homegroup the normal way, I get the message "Windows cannot set up a homegroup on this computer".

I checked into it, and found out the "Peer Name Resolution Protocol" service needs to be started for the homegroup to work properly. When I try to start it, I get this error:

(Error 0x80630203)

This computer is running 7 Ultimate x86, upgraded from Vista Home Premium x86.
The computer that created the homegroup is running 7 Ultimate x64 upgraded from Vista Ultimate x64
The other computer that connected to the homegroup successfuly is running a fresh install of Windows 7


New Member
See this thread,,, do everything in it to see if it resolves the issue. Ignore that it is for XP.
The problem is probably related.

Basic Samples

Reason,,, 0x80630203 = PEER_E_DATABASE_ACCESSDENIED = The requested access to the database has been denied.

Last edited:
Thank you so much. Here's what I did to fix it:

1) Went to C:\Users\All Users\Microsoft\Crypto\RSA

Set Group "Everyone"'s permissions on the folder MachineKeys to Full Control
Set my current user's permission on the UserSID folder to Full Control

service started perfectly!


Senior Member
Where's UserSID?

Hi, trying your solution, managed first action but cannot find UserSID folder. Where will I finds it?

This website is not affiliated, owned, or endorsed by Microsoft Corporation. It is a member of the Microsoft Partner Program.