This is for anyone who is using the Advanced System Care software for computer maintenance: if you've upgraded to version 4, you've run a "deep care" and all your most frequently used software list (from the start menu) has disappeared.
It's easy enough to find how to set your registry entry back to get the MFU back. Just Google it.
My problem was, I couldn't find anywhere how to prevent Advanced System Care from doing this in the first place. I first assumed it was the registry optimizer because it's a registry entry, so I pored through several hundred registry problems after running "scan only" and it wasn't in there. Next I took a wild stab that it was part of system security since it sort of had something to do with history. No luck there, either. So here we go.
First, follow the instructions that you can find pretty much anywhere to set your NoInstrumentation setting back to bring back the MFU list. This will cause ASC to find an "error" again. Go to "deep care," uncheck everything except "system optimization" and run "scan only." There will be a registry entry with a registry value of NoInstrumentation. First uncheck it so that it doesn't keep setting the entry to their "recommended" setting, then right click on it and select "ignore" so it ignores it from then on.
I guess maybe getting rid of the MFU list can make somebody's computer somewhere run faster, but to me having no MFU is just a big pain in the @ss.