right click.
=> or another method to kill your explorer.exe.
But if you don't see IconCache.db , even with the windows search tool / restart PC,
you have another problem on your PC.
Can you write the path where you searched for IconCache.db ?
All precedent advice were from members, for simple / easy solutions.
In your case, if you are sure IconCache.db is nowhere (after have verified all the paths
given in above posts and with windows search tool), you should make a post here : Malware Removal Assistance