Never played with wireless so this is a stab in the dark .....
can you get your laptop to "see" the PC? If so, you can wander around with the lappy and check the coverage inside your home. If that works, you can then play with the PC in various locations and optimise the siting of a permanent wireless router/hub/modem.
There was an article in PCW either last month or the month before that pointed to some wireless diagnostic/sniffer software (freeware or shareware from memory) that would identify wireless access points and indicate their openness. If I can find that when I get home tonight, I'll point you at it.
Good luck
ST