Per nestork:
to just plug my PS2 mouse and PS2 keyboard into any of the USB ports on the new computer.

Also, I'm being told by tech support at IOGear, that I CAN't use PS2 to USB adapters with my PS2 KVM switch. They say it wouldn't work...

Some years back, I was where you are now: Multiple PC's and a switch to
jump back-and-forth.

Then I discovered TeamViewer....

It's free, and it does the job: almost instantaneous connection, works
locally or remotely, the connections can be left active so it's just a
matter of switching windows (i.e. even faster that a manual switch)...

As far as I can see, there is just no downside compared to a switch.

The only fly in the ointment so far has been a customer that will not
let me TeamViewer into my PC at their site. Instead, I have to connect
using one of their PCs over VPN... and they don't want TeamViewer on one
of their PCs.

The solution to that has been my existing keyboard/mouse setup: a
"Microsoft Wireless Multimedia Keyboard 1.1" and a monitor that supports
both DVI and analog inputs.

I can re-plug the single USB connector for the keyboard/mouse just about
as fast as I can flip a switch. For the monitor, I connect my
monitor's DVI port to my PC and it's analog port to the customer's PC.
Takes a couple of seconds to tell the monitor to swap inputs, but it's
livable.

So, for your situation... bottom line.... TeamViewer. It's a
no-brainer as far as I can see.
--
Pete Cresswell