CEE Relays Ltd

Tel:   +44 1753 576477    Fax: +44 1753 825661
FAQs: Eliminating Start-up Errors (Deleting the Registry Key)
If PTW fails to start and gives a general protection fault (GPF) error, the most likely cause is a corrupted registry key. The solution to this problem is to delete the PTW registry key and then start PTW. PTW will automatically recreate the registry key.  It may also be necessary to delete the registry key if you are changing from a local hardware key to a network hardware key but do not want to completely re-install PTW.

WARNING: The following procedure should only be used for deleting the registry key of PTW.  Other Windows programs have their own registry keys; these should not be tampered with as it can lead to system instability, loss of data and potentially prevent some programs from running.
To delete the PTW registry key, there is a special tool found in your Windows Start menu under:  Start>>Programs>>PTW>>Delete PTW32 Registry Key

Alternatively, run the RegDel.exe program in the PTW32/BIN directory. 
PTW Registry Cleanup
In the dialogue box which opens (pictured above), select the "Clean up ALL settings in the registry for PTW" option, and then click on OK. 
PTW should then start properly. 
Please note that each user has a unique registry key, even if both users run PTW from the same computer using different login credentials.  Therefore if one user is having problems running PTW and another is not, the RegDel program must be run with the "problem user" logged in.

Unlike the main PTW program (or other, standalone, software) the ArcCalc program does not use registry keys at all.  If you are using ArcCalc and experience start-up errors, please contact us.