Have you ever worried that someone who has access to your PC for a short period of time may be able to steal your SolidWorks serial number?
SolidWorks provides an easy way to hide the serial number in the help about dialog while leaving just enough of it so that calls to support can be uniquely identified. The part not hidden is used mostly for internal communication between SolidWorks corporate and the VAR and referred to as the Seat ID. The only reason it's only used internally is because by the time you explain to someone what the Seat ID is you could have just asked for the whole serial number and figured it out yourself. But if both parties know that you’re talking about the Seat ID it's not a problem.
Here's the solution:
1. Make a new text file (name it something like 'Hide SW Serial Number'
2. Paste this text into the file:
Windows Registry Editor Version 5.00
"Serial Number Hide"="1"
3. Save the file
4. Change the file extension from .txt to .reg
5. Make sure SolidWorks is closed and Double-click on the .reg file and click Yes when it asks you to continue and OK to confirm the changes have been made successfully