If your desktop is on a wireless network, you should be able to access it.
Make sure that your ipaq is set to the same ESSID or BSSID as your desktop. This id is basically the "network name".
Make sure that your ipaq is set to a static ip/subnet address that does not conflict with another periferal that is on the network. If you're not able to set the IP, and your AP dishes out the IP through DHCP, or if you have a DHCP server that does that, then make sure that you're ipaq is set to dynamic IP, and set the gateway if you need to.
Basically, match the settings of your desktop's nic. The only thing you cannot do, is have the exact same IP. Also, if you're using WEP, make sure that you're using the exact same KEY value, and key. So if you're AP is using key 2, on a 1 through 4 scheme, make sure that you are using the second key (key 1 on a 0 through 3, or key 2 on a 1 through 4). This way you're apples to apples.
One last thing... if you're access point is using long RF preamble, or not, make sure you're using the same setting.
Hop
PS If you're using a Symbol AP, this is more straight forward than using a Cisco AP sometimes. This is because that even though they're both using most of the same settings, they sometimes call the same thing something different than the other
MFG.
Hope that doesn't confuse you more than helping you.