Solidworks Spur Gear Generator

Hi
I'm generating spur gears using the toolbox without and difficulty. The file, located in Solidworks Data - Copied Parts, is read only so i save it to my project file.
I then need to modify it by, for example, modifying the root of the tooth and adding spokes. This i can also do successfully saving it in my project file.
I create an assembly with a number of modified gears and all is well.
If i close Solidworks, re-start it and open the assembly and rebuild the assembly it changes the gears from the modified version to the origanal unmodified gear in the copied parts file. However, if i save the modified gears in the copied parts folder then all is well.
Is there a way of preventing the assembly from reverting to the original toolbox generated gear and use the modified one stored in my project folder?

I have just copied some modified gears onto a flash drive and copied them onto another computer running SW.
I save them to a new folder and build an assembly from them. All's well.
Close and re-open SW and once more the gears revert to the unmodified version! Strange.
I guess it must, in some way, need the toolbox information to draw the gear and ignores my modifications.
The files are extraced from c:\solidworks data (2)\browser\iso\power transmission\gears\spur gear_iso.sldprt not C:\Users\Bob\Documents\Wooden Clock where i saved the modified files.

For all practical purposes parts generated by the Toolbox are read only, they can not be modified. I find the easiest way round the problem is to save the part as a "dumb" file and then reopen it. I usually save it as a parasolid file, you can use Step or Iges, they all work, parasolid seems to give better results for me. Dave.

That seems to have done the trick. As with most of these problems the answer is obvious once revealed. There was a further problem which i'm sure your solution will resolve. Using Solidcam to generate toolpath worked OK but once more when i saved the file either in Solidworks data or the project file it disappeared into the ether. If i changed the part i had to regenerate the tool paths.
Thanks a million.:banana: