Laptop to Desktop Network Disappeared!

First of all, I love that I found this site. I'm the computer technician in my home, but lack any sort of expertise in the subject. I'm in awe of tech geeks. Since my other question was answered so quickly, I thought I'd give you this puzzle. I have a router that connects my desktop and laptop. Both are Windows XP and it's worked fine for a month. Just yesterday, I tried to print and it failed. On further investigation, I realized that my Internet connection (via router) is working fine, but my file/printer sharing isn't. When I click on "Network Places" on my laptop, the desktop files no longer show up as they once did. When I open "Network Places" on my Desktop, I see the laptop files, but when I click on them it says that I don't have access. I have restarted both computers mulitiple times hoping it was some weird bug.

Does anyone have an idea of what's going on? When I networked everything for the first time, it was insanely frustrating for me and I can't even tell you what I did, so I don't think I can "re-network" if you suggest it without a guide. I'm hoping I won't have to re-network.

Thanks for your time. I really do appreciate it. Stephanie

 

Firewall???
Have you installed or made any changes too?
File/Printer sharing is enabled?

 

The only major installation that I remember doing was for a defunct Incredimail download. The Incredimail (upgrade) didn't work and so I reverted it back to the point that I created with System Restore. That was over a week ago and I hadn't noticed any differences in the network, however, it could be possible that I didn't need to share any files or print since then. File/Print is enabled. Firewall has the same settings as before - I'm not an expert at it, but I don't believe I have a firewall. If I do, I remember inputting each computer's numbers (ip address?) so that they could receive info. from one another. Sorry I'm so computer illiterate. Did I give you enough to work with?

Stephanie