Dimension 4550 Network problem, HELP

I recently reinstalled Windows XP and wiped my hard drive clean.  I reinstalled pretty much every driver and program I need.  But one thing is stil not working..my network.  I cant read any shared folders from thsi Dell and when i share a folder on here, i cant see it on any other computer.  I need to share folders for this comptuer so any help would be greatly appreciated.  Idk if it means anythign but i use a linksys wired router.  ive tried seting up the network and it goes through the wizard as if it would work but it doesnt do anything. it seems as if my computer thinks its on teh network and that its fine but i cant access anythign through it , please help