Hi DennyD,
my first suggestion would be to back up what you can and do a clean install. We have had many users posting with problems after upgrading and the solution is almost always a clean install.
If the above is totally impossible, you could try re-installing your sound driver (or seeing if a later version driver is available)
As for the flash player, sometimes multiple copies of flash player start to conflict and the only cure is to un-install them. The un-installer can be found here:
How to uninstall the Adobe Flash Player plug-in and ActiveX control
Once you've un-installed then re-install....
I'd still try the clean install though..