Would like to transfer my license from one PC to another PC

You just need to transfer a license file by using "Reconfigure Software Licenses" option on PTC's site, here: http://www.ptc.com/appserver/lm/rsl/reconfig.jsp.

Also, when creating a request for a new license, you must specify the new MAC-address (from a new PC).

@EG_7492478

You can install Mathcad and activate license online using your product code.

1. Complete the installation of Mathcad 
2. After successful installation, Launch Mathcad
3. Select “M” on top left > Options > License > Get License 
4. Activate Purchased License > Next 
5. Enter your PTC account credentials > Next
6. Enter Product code > Next and compete the task.

I hope above steps will help you. 

Thanks.