Plazz

When I had this problem Siemens Support sent me the following which cured it...Step 7 v11 - Continuous restart error message

In an attempt to resolve the issue you are seeing with Step 7 v11, can you please implement the following;

1) Save the attached file to your local hard disk and then extract the S7DOS del reg if error 1605.re_ file.

2) Then rename the S7DOS del reg if error 1605.re_ file to S7DOS del reg if error 1605.reg

3) Double click the S7DOS del reg if error 1605.reg file and click 'Yes' to add the information to the registry and 'Ok' the execute message.

4) Run a repair of the Step 7 v11 install( in ur case v12)

Note: Always take an export (backup) of your registry before making any changes to it; please refer tohttp://support.microsoft.com/kb/256986 on how to do this.