This may not fix it but there's no harm in running it, it's called ccleaner, it has a registry cleaner that work's very well.
Make sure it's updated then on the left it will say registry, run it and if you want to back it up you can but I never had to, run it till it find's none then reboot.
I've been using it for year's with no problem's. Run it everytime you uninstall anything, even driver's.
Here is a link for it, it's up in the right corner,
Download CCleaner 2.18.878 - FileHippo.com
As far as the freezing goes I would go into safe mode and uninstall the flash player then reboot.
You may end up reinstalling w7, if you do, save what you need.
If you reinstall over it it will create what is called windows.old, it will have pic's and other stuff in it.
When I installed mine I replaced all the driver's with vista one's for all the hardware.
I just don't know what would cause everything not to respond.
Hope this help's.