The runbox always shows the last used commands. A scammer can get suspicious when he/she finds not common used commands like taskmgr, msinfo32, services.msc, a.s.o in the history list. It is therefore wise to cleanup the runbox first before starting a prank session.
- Start the registry editor (regedit.exe) -> CONTROL R + regedit
- Move to HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Explorer\RunMRU
- Select the entries you wish to remove
- Press the Del key (or select Edit – Delete) and click Yes to the confirmation