The above would work but is abit extreme in the first instance. I would delete temp files, cookies for starters. I would also uninstall flash (theres a tool on the internet somewhere to do this) then reinstall it with newest version from adobe website. The fact it says flash player is out of date has to be a good start. With the new flash, if your still having problems i would then create a new windows account. These weird sort of problems can often be profile specific, so by creating a new profile and logging into the PC as that you eliminate these issues. If it works copy all you favs, my docs etc into the new profile and continue as you were before.

If none of the above helps get some anti spyware programs and do full scan to make sure the PC is clean. Also make sure windows updates are all uptodate. Failing that assuming your using Internet explorer then download firefox and try that. It it works then at least you will know it is a browser related problem.

Hope that helps!