Not yet upgraded
We recommend deactivating the license before upgrading to Windows 10. You can do this by starting BricsCAD, and clicking [Help > BricsCAD License...] in the menu bar. Here you will find the deactivate button.
Once upgraded, you can activate with your activation key as before.
Note: this only applies to online activations. Manual activations will not be affected.
V14 or older
If you have upgraded with V14 still activated, you might get an error "The license for this product is locked to another computer or is using an invalid hostid" (error -4).
In this knowledgebase article is described how to resolve it.
V15 or newer
Upgrading with V15 or higher should not cause any problems.
If an activation dialog appears when starting BricsCAD, enter your activation key in the dialog and BricsCAD should start.
I want to upgrade, or have upgraded to Windows 10.