Setting up the remote debugger from Windows 8 (Visual Studio) to Windows XP SP3 (Program) was a fight, but I won. Read my steps below.

Program machine ~ virtualxp

1. Add a user for remote debugging that will be available on destination and developer environment (~remoteaccess)
2. Install Visual Studio 2010 Remote Debugger
3. Change security policy to allow remote debugging between domains
   
4. Reboot!
5. Login with user for remote debugging
6. Start Visual Studio 2010 Remote Debugger and note the name of the server (Msvsmon started a new server named ‘RemoteAccess@virtualxp’. Waiting for new connections.)
7. Start the application to debug

Visual Studio machine

1. Add a user for remote debugging that will be available on destination and developer environment (~remoteaccess)
2. Start Visual Studio 2010 as the user for remote debugging (Add option to Windows 8)
3. Debug > Attach to Process … > select process and Attach
   
4. Debug > Windows > Modules. Displays modules that have matching PDB files found and the possibility to load extra (PDB) files

I disabled both Firewalls. They will be in your way.