As reported here https://www.board4all.biz/threads/solved-coder-reverser-help-needed.750243/ normal uninstalling with Revo Uninstaller or Total Uninstaller leaf the key in the system. A helpful user in a other forum found the reason Code: C:\Documents and Settings\John Doe\Application Data\Light Developer delete the "InstallFlag" file and ... regedit. [HKEY_USERS\S-1-5-21-596416313-346948869-1116582277-1000\Software\Stepok\Light Developer] "InstallFlag"=hex:77 xx xx xx delete InstallFlag reg binary. note ... on 64 bit systems there may be another entry's for Light Developer "InstallFlag". this reverts registered Stepok Recomposit Pro to trial. I tested it in a Win 7 x64 and it was working there on the same way. starting on this point deleting this file and this key which results and my question is now, who is able to write a cleaner that works on x86 and x64 systems with this given information?