Answer: You have a couple of options. Since you are planning to purchase a new desktop computer in your office already I recommend creating a peer-to-peer network, mapping the drive from the second computer to the networked computer and to stop using the server. This is supported by Sage as well. In this configuration, we would highly recommend online internet backup of your Sage 100 ERP (MAS90 files). We use Divinsa for many of our clients for this.
Another option would be to move the Sage MAS90 installation to a cloud based provider, you would however still need the two in-house computers, so it may be more economically to go with the first option.
Thank you Mike Renner Owner at Computer Accounting Services and authorized Sage 100 ERP partner, headquartered in Indio, CA.