lost network locations

hello, new to the forum here. after many days trawling the web for info on my problem i thought this looked the best site to find the help i desperately need. my set-up is :
I have a virgin cable modem connected to a belkin G plus Mimo wireless router. the router is connected to a pc (vista basic) by ethernet cable and also wirelessly to a laptop (Xp pro). I was only using my network for file-sharing because the USB ports on the laptop do not work. I have a dynamic broadband connection but have set ut static ip addresses for both systems as i use P2P. all i had to do was open the network folder on the pc and the laptops icon would be there and would take me to the shared folders. All was well until a few days ago when the icon for the laptop was missing from the network folder on the pc. After some trial and error i found the static ip address for the laptop had been altered (maybe windows reset the network adapter when trying to diagnose the problem?). Once i corrected this the laptop came back online into the network but the next day when i switched them back on and tried to access the laptop from the pc i got an error message saying couldn't access the network maybe i didn't have permission check with administrator. again i searched around for days but could not find any info to help me on the net. I tried naming both systems in a workgroup but could not find the laptop from the pc. i could find the pc in the workgroup folder on the laptop but was again told no access might not have permission. also sometimes my routers icon would be in the network folder and other times not, i can see it and refresh and it dissappears and vice versa, strange i think. i had zonealarm running on the pc so i deactivated that and found i could now access the pc's public folders from the laptop via the workgroup folder but not the other way round (can't find the laptops shared folders from the pc). This is enough for me at the moment but my network still cannot be correctly set up as the laptops icon still does not appear in the pc's network folder when i would think it should being that they are both connected to the modem/internet through the same wireless router. i would hope someone would recognize this problem as it is probably quite common and could help me out with maybe a troubleshooting checklist of some sort or even just some advice as i have tried everything i can think of and maybe have altered a wrong setting somewhere in my blunde3ring. sorry for the long winded post but just trying to include everything i can think is relevent. if any other info is needed just ask, thanks in advance...