Sharing internet, cannot share files or printer....

I have an HP desktop, P4 1GB RAM & a HP laptop with 802.11b/g wireless access. Both running XP Home with SP2 and even the latest MS patches. I have a Linksys wireless router. I was previoulsy able to share internet, folders and printer. However, recently all I can do is share the internet. I'm not sure what has changed. I've scanned my system numerous times for spyware, malware, viruses, etc. and found nothing, using PC-Cillin IS 2005 (installed on both machines), Symatec (online), A-squared, Ad-aware, and Spybot. At this point, I don't think something sinister made changes or corrupted the networking.

I have used the Network Wizard - nothing. Basically, my two pc's cannot see each other. I've tried to ping each other via their IP addresses; however, they time out - not able to see the other pc. I've also tried to ping each other using their respective pc names - nothing. They can ping and find themselves, but that's no help. Both pc's are on in the same group - MSHOME and both have different names - DESKTOP and LAPTOP (I am simple.) I have spent countless hours searching forums, Microsoft support, etc. Nothing found to really address this issue. I have not turned off my PC-Cillin firewall; however, this was not a problem before. I've also turned off the windows firewall completely. Nothing seems to be working. Any suggestions would be greatly appreciated. I'm pretty much a novice at this, so please be patient and think in simple terms. Thank you!!