Using RegEdit?

There are several software programs that have not been installed on my computer for years. However, I keep finding references to them every now and then -- even after running Ccleaner's Registry Cleaner and Registry Mechanic. Many of them even still show up in the Application section of CCleaner.

Is it safe to find the folders referencing these various programs under the "Software" section in RegEdit and simply delete them? If that's OK, I assume that deleting them will clean up the problem so that they're no longer found. Right?

Maybe, if you definitely know for sure it isn't installed anymore.

You need to be careful with some references in the registry that Microsoft has there in default installations of Windows which are there for compatibility reasons - mess with those and who knows what can of worms you'll be opening.