Windows 7: I call my home network a workgroup

Wife and I use desktops, I have a second computer that I use the same monitor, keyboard and mouse with. I also have a laptop. They are not allways on at the same time but sometimes they are, they all work well together either way. My Question is this:

Wifes compouter shows up two ways. When I go to Start/computer, my tow drives show up as C and D, the two CD/DVD drives show up as E and F and wifes drive shows up as the EXTERNAL G drive. Now I click the network entry Shows up as Margaret drive. If I have the laptop and the second computer they show up as Y and Z drives. The never show up as EXTERNAL DRIVES.

Now I have the special cables and power suply that allows me to connect a SATA or IDE drive to a USB 2 port which allows me to use these extra hard drives for storage. When my wifes computer is not on, and I plug in one of the external hard drives it shows up as the H drive which would be expected. As soon as shee truns on I no linger see an H drive so am unable to see the drives.

It appears that all of the USB PORTS are OK, the USB controller appears to be OK. Why would Wifes computer being on effect anything on my compouter. Also the system, all by it's self decided to call her computer an external drive and not call my two extra computers ext drives.

I use a Linksys 4 port router with a wireless access point for the laptop, all the others are hard wired to the router.