The .Net Framework 3.0 refused to install on my machine this morning - a quick look through the installation logs (particularly
C:\DOCUME~1\<your user name>\LOCALS~1\Temp\VSW1\VSSWMSIFailInfo.txt) revealed the following:
Error 1402.Could not open key: HKEY_LOCAL_MACHINE/SYSTEM/CurrentControlSet/Services/Eventlog/Security/ServiceModel 184.108.40.206. System error 5. Verify that you have sufficient access to that key, or contact your support personnel.
I am a local admin on my machine, so this surprised me a little. The permissions on this key were set to grant Full Control to the ASP.NET user. I granted myself Full Control, but this didn’t seem to help. Granting Everyone Full Control seemed to resolve the issue - other keys in the subtree grant Full Control to the local Administrator group and the System user, so I revoked permissions from Everyone and granted these access to the key once the installation was complete (ah, the power…).