If you receive the message your serial number is either missing or incorrect when attempting to launch TurboCAD you will need to manually enter your serial number into the computers registry.
1) From the start menu select Run…
2) Type “regedit” into the “Open” field and press OK
3) Browse to the folder HKEY_LOCAL_MACHINE SOFTWARE IMSI TurboCAD Professional v12 (or whichever version of TurboCAD you have installed)
4) Right click the “SN” entry and select “Modify”
5) Type your serial number into the “Value data” field then press OK
6) TurboCAD should now open up correctly and the serial number should stick
