I'm trying to install SQL Server 2008 R2 Express from this site:
http://www.microsoft.com/express/database/
I have a 64-bit, Windows 7 machine.
I have tried both the 32-bit and 64-bit versions but each fail on "Performance counter registry hive consistency".
How can I fix this so that I can install SQL Server 2008 R2 Express?
You can skip the Performance counter check in the setup altogether:
setup.exe /ACTION=install /SKIPRULES=PerfMonCounterNotCorruptedCheck