Vista - Vsta Wireless Network Problems and Questions

Two Machines.
Desktop (DT) and LT. NW = network

Attempted Ad Hoc network several times. Network name: NIA

Vista has kept each attempt....somewhere...despite my removing them. The DT
has NIA 8; the LT has NIA 2.

I installed router: D-Link 625.

Both computers show in Network Map on both computers. LT can open files in
DT; DT cannot open files in LT. Ping from DT not recognized by LT. Internet
connection on both computers working.

NW diagnostics cannot find or correct problem.

Permissions and sharing set...I think...to allow full access and control.

1. Is there a way to completely delete the earlier failed networks?
2. What is the consequence of having one computer connected to NIA 8 and
the other NIA 2?
3. I wish to have the network originate on the LT so that I can wireless
NW with other computers in other locations when I take the LT there. How do I
confirm which computer owns the NW?

What should I do to access files on the LT from the DT?

What can I do to reset networking on both machines and start afresh?

NOTE: "Network Magic" and "McAfee Easy Network" are running on both
machines. I do not want to use either, but in desperation tried them.

Any help will be appreciated.

Jim