Hello! I'm Jen, and I'd be happy to help you out with this issue.
I'm sorry to hear you're experiencing this issue. To setup multiple monitors on Windows, please ensure that your cables are connected properly to the new monitors. Then, go to Settings > System > Display. The monitors should automatically be detected, but if not, then select Detect. You may also check the following links for more information.
https://support.microsoft.com/en-us/windows/set...
https://support.microsoft.com/en-us/windows/how...
I hope this information helps. If you have any questions, please let me know and I'll be glad to assist you further.
Best Regards!
Jen :)