VSTs Not available/not scanning

Are you running SONAR 64 bit or 32 bit?
 
If the VstScan button in preferences is grayed out it means that SONAR cannot find the vst scanner. There are two possible reasons for this:
1. The scanner itself is missing. The installer typically puts it here:
C:\Program Files\Cakewalk\Shared Utilities\VstScan.exe
 
2. The path to the scanner is not found. It should be in the registry here:
HKCU\Software\Cakewalk Music Software\SONAR\Cakewalk VST X64\VSTScanPath
 
If the path in 2 is not found SONAR will not scan any vst's. To restore the path you can force personalization again.
To do that exit SONAR, then relaunch SONAR by clicking its shortcut in the start menu while holding down the shift key. This will launch SONAR and show the personalization dialog. Allow it to proceed and personalize.
This should restore the missing reg key to the VST scanner.
 
If that doesnt work try resinstalling SONAR and redo the personalization. Somehow something removed the path to the scanner on your system. Either a reg cleaner or a failed install possibly.

Did you get the personalization prompt?
You shouldn't need to uninstall. Where are you doing the scan from?
Please do it from SONAR's preferences | VST dialog.
Also check if VstScan.exe is found here: C:\Program Files\Cakewalk\Shared Utilities\VstScan.exe