I tried putting it in another folder but the same problem happens; disappears after a few reboots.

Quick launch disappears Solved - Windows 7 Support Forums

I have the same problem with my S3 on Windows 8. Only solution is to restart your computer. I tried troubleshooting the hardware and nothing works. I have tried Kies, newest USB drivers, etc. Nothing...

This worked for me in Windows 7. It works on Windows 8 too, BUT only temporarily. It goes away after a few days. Anyone know a fix? Thanks.