The installation is blocked

I'm trying to install VS 2012, but it just gives me the error: "This product did not install successfully: The installation is blocked."

I'm on Windows 7 and I've had VS 2010 installed and I think 2011 beta as well (possibly even 2008). I uninstalled 2010 using the utility found here: http://archive.msdn.microsoft.com/vs2010uninstall

... but there is still lots of cr*p in my list of installed programs, such as:

- Microsoft Visual Studio 2010 Service Pack 1 (I tried to uninstall this but it didn't seem to work properly)
- Microsoft Visual Studio 2010 Tools for Office Runtime (x64)

... and loads of other things like C++ redistributables, ASP.net, SQL Server, etc.

Here is the log file: https://skydrive.live.com/redir?resid=3452008C432A26F2!120&authkey=!ACle-A4cyRMBS_Q

Please help.