Networks network sharing with external hdd

ok i am haveing trouble with sharing
heres the set up i have 1 computer conect wired to the wireless network wiht a 40 GB maxtor usb 2.0 external harddrive
2 laptops 1 ibm X40(barnd new ) mine 1 ibm T 30 moms both running wireless and all computer runnign win xp pro

heres what i need to happen i need to beable to view all files and share and share all printers even on the external drive

i set up all computers for same workgroup and file sharing but when i try to connect with any computer it says "list of servers for this work group not avilible" but it was working last nite for 5 minets and even then when i try toopen files on the T30 the other 2 computers would say acess denied
but i enabled file sharing and all that

please help i know i being demanding but my mom pissed that she dosnt have her laptop back yet and i running low on time to do this