Stuck trying to get any version to work - 3.6 installed and broken

I installed 3.6 a few weeks ago but did not try using it until now. None of it works. I get the whirly thing for a few seconds then nothing.

I see many problems with 3.6 on windows 7, so decided to try 3.5, but 3.6 will not uninstall - it fails saying the process was interrupted. Sop I cannot install 3.5 either.

What should I do now?

I recently changed from 3.5.4 to 3.6.1 without any obvious problems except for a few possible bugs. On 11/Oct/2012 I installed a number of Windows 7 updates and turned the computer off. Next use was today [22/10/12] and LO 3.6.1 would not open. I kept on getting “LO is broken” messages. Re-installation of 3.6.1 and an attempted reversion to 3.5 did not fix the problem, but a new installation using 3.6.2 is working beautifully and the ‘bugs’ that seemed to be in my 3.6.1 version have disappeared.

To have both version installed, you need to do a parallel installation, otherwise you can install 3.6 over 3.5 but not the inverse, you must uninstall 3.6 first.

http://wiki.documentfoundation.org/Installing_in_parallel#Windows