It might be that the loaded driver for the adapter has been corrupted and it will not be overwritten by a correct driver until it has been un-installed.
Please try this. Plug in the adapter on it's own and then go to Windows Device Manager.("Control Panel", "System" and then click on the Hardware Tab). If there is an "Unknown USB device" there or a "Pico Parallel Port" with a yellow warning triangle under USB controllers, left click on it once to highlight and then right click to bring up a list from which select "Uninstall". Once that is done, unplug the adapter and then plug it back in again. The Windows "New Hardware Found Wizard" will run. Follow the on-screen instructions and, if the wizard asks to connect to Windows Update, select 'No' and allow Windows to automatically detect and configure a new driver after which the adapter should show up in device manager again as a "Pico Parallel Port". If you get that, your adapter should now work.
If you still have problems with the scope not being recognised, please try to eliminate the scope by seeing if it will work on another PC that still has a parallel port to drive it directly. If you are unsure which item is faulty, I can arrange for both the scope and adapter to be returned for checking and we will tell you the result. In that case, please contact via the Help desk:-firstname.lastname@example.org
If the adapter is less than two years old, it is covered by the warranty.