Windows 7 laptop cannot access files or printers on Windows 7 desktops

I have an HP Pavilion dm4t-2100 CTO Entertainment Notebook PC running Windows 7 Home Premium 64-bit, the OS with which it was installed. I am connected to a Homegroup which also contains a laptop and two desktops. I am able to connect through the network to the other laptop and remotely view files and devices on that laptop. However, I cannot see past the names of the two desktops. This means I cannot read or write files on or install devices connected to either desktop computer. Essentially, here's what's happening:

The desktops can see each other and both laptops (R/W). The laptops can see each other (R/W), but neither one can see either desktop ("Cannot find the network path"; ping command fails).

Is there a setting I can change either on the laptops or on the desktops to enable connectivity? All computers on the network are running genuine copies of Windows 7 Home Premium 64-bit as their original OS.

Check that the desktops are in the same workgroup as laptop and turn off password protected sharing if on. Share folders on the desktops you want to access, choose Everyone and set to read/write...

Been there, done that. I think you're missing the problem here. The laptops CANNOT ping either desktop by name.

Quick update - I am able to ping the desktops by IP. Unfortunately, I get a password block in Explorer even though password-protected sharing is disabled. I cannot change the logon domain from LOCAL to CLIENT (where LOCAL is the name of my laptop and CLIENT is the desktop's name).

In addition, my print spooler won't start. I'm running an sfc /scannow as I speak.

EDIT: sfc /scannow found nothing.
DOUBLE EDIT: It seems to have been fixed, albeit temporarily and without my understanding. I'll monitor the situation.

Okay, here's what I've determined. The two laptops were connected via the recently-antiquated access point on the router (2WIRE384) instead of the new WAP (Linksys). Switching the wireless connection from the 2Wire to Linksys solved the problem.