severe registry errors???

Download HijackThis!
HijackThis - Trend Micro USA

Right Click to run as Administrator, 'Do a System Scan and Save logfile'.
The HJT log will open in notepad. Copy and paste the HJT log back here.

Was this an upgrade from Vista 64bit?

I see signs of Norton, is this just for backup, or?

Open HJT and rescan.. check these items:

R3 - URLSearchHook: (no name) - *{CFBFAE00-17A6-11D0-99CB-00C04FD64497} - (no file)
O2 - BHO: (no name) - {5C255C8A-E604-49b4-9D64-90988571CECB} - (no file)

Close all browser windows, except HJT, then click 'fix checked'.

Reboot your computer and tell me what's going on now.

Okay, uninstall Norton using the Uninstall/Removal tool
Download and run the Norton Removal Tool to uninstall your Norton product | Norton Support

Rescan with HJT, check this item:

O2 - BHO: (no name) - {5C255C8A-E604-49b4-9D64-90988571CECB} - (no file)

Close all windows except HJT, then click 'fix checked'. Exit HJT and reboot.

Next, uninstall AVG. See if you can get Microsoft Security Essentials up and running by right clicking on the file and choosing to run as administrator.

Let me know if this is working now.

Couple other thoughts here...
See this about MyWinLocker
Startup details - mwlDaemon (mwlDaemon.exe)

Also, Uniblue\RegistryBooster\cleaner may have done some unkind things to your system's registry.

If you have a restore point saved by Uniblue, to the time before you couldn't open any program files, then I would suggest that you merge the 'fix' back into your registry. Uninstall Uniblue.

A 'repair' install is most likely going to be the way to get this computer back to normal again.

I've been following the thread. I agree with Jacee.
Here is the link to the tutorial.

Repair Install

Have you even tried SYSTEM RESTORE to a date BEFORE this started happening??? Its a life saving tool, really. If that were to fail as well or do no effects, then you would in deed need to do a repair install.

If you are using a registry cleaner, always reserve a full registry backup with a free program called Erunt, reserve a restore point, or even a system image. Unless you have proper knowledge on how to clean the registry, its not recommended for you. I still use registry cleaners now but I have learned my lesson in the past, the hard way. I was a misguided user by then.