wireless networking

[#1]

hey guys,
wondering if any of you could help me. Last summer i had a wireless network setup fine in my house between my computer and my laptop using my router downstairs, and was able to transfer files back and forth and printer share etc.
However i went away to uni and then came back again and now, having used the network setup wizard again i can't get it to work at all. both laptop and computer have no problem connecting to the internet themselves, but when i go on My Network Places the shared files of the other just does not appear.
any suggestions?
thanks,
tim

[#2]

yea sorry,
i realise i was a bit rushed when i posted this and did leave out quite a lot of information. both computers are running winXP professional, both with all the latest updates. and yes both computer and laptop have been made part of the same workgroup.
I have checked and double checked that the share permissions allow files to be accessed on the network, so i know it is not because of this.
My laptop and computer have different log-on details, both username and password. there never appeared to be a problem using the wireless network last summer. However since taking my laptop to uni and connecting it with their network (wired), i have been unable to get my laptop and computer to talk to each other, although i do not see how this itself could have caused a problem.
Hope you guys can give me some more help,
tim

[#3]

status update: currently working atm, as have just reset everything, so fingers crossed

[#4]

Good news   Hopefully all will now be sorted!

[#5]

Quote from: James

Good news   Hopefully all will now be sorted!

alas no, as expected it no longer works, only for a brief moment. when i look in My Network Places the computer name for shared documents of the other computer is just "unknown".
all help would be appreciated,
tim

[#6]

Do Check your Firewalls as James_H suggests. I have had this before where the SOFTWARE firewall needs to be told to ok the other PC address Zone Alarm has caught me out on that once or twice!