Need more memory on remote windows computer

You can follow the procedure in the following document to expand the EBS volume of a Windows instance.
https://repost.aws/knowledge-center/expand-ebs-root-volume-windows

If you want to increase the memory, it is possible to do so by changing the instance size to something larger than it is now.
https://aws.amazon.com/ec2/instance-types/?nc1=h_ls
https://docs.aws.amazon.com/AWSEC2/latest/UserGuide/ec2-instance-resize.html

Navigate to "Volumes" under the "Elastic Block Store" section of the AWS Management Console's EC2 Dashboard. Choose the volume you want to change, then click the "Actions" dropdown. Choose "Modify Volume" from the list, and then change the size to your preference in the prompt that appears.

It is important to note, however, that once the size of an EBS volume has been increased, it cannot be decreased. As a result, before changing the volume size, carefully consider your storage requirements.

The changes to the EBS volume size must be recognized by the operating system. To increase the volume size on a Windows machine, you may need to use the Disk Management utility.

It is also critical to backup your data before performing these operations to avoid data loss. It is recommended to have multiple backups of mission-critical data in different locations.

Please keep in mind that increasing storage may result in additional costs, so it's best to check the pricing details on the AWS website or contact AWS Support for specifics.