Yes, you can purchase additional vCPU, RAM, disk space, and bandwidth resources either during the VPS signup process or later when you need them.
How to Order Add-ons
The easiest way to purchase add-ons is through the member portal. Simply log in to your client area, select your VPS service, and choose the additional resources you wish to add.
For detailed instructions, please refer to this article: Windows VPS Plan Changes.