- Have Skype installed and running
- Install the XP CIT-300 driver, do not launch CIT 300 yet. If the installer does not wish to install because of whatever it wishes to not like, install the software on some XP box and copy the c:\Program Files\Linksys folder someplace onto drive C and create a shortcut
- Find cit300.exe in c:\Program Files\Linksys\CIT300\ (or Program Files (x86), in case of 64-bit windows). Go into Properties, Compatibility, and select "Run this program in compatibility mode", select XP service pack 2. On the bottom of the same windows you _may_ have to select "Run this program as administrator".
- In case you have the base all plugged in at this moment - unplug the power cord to the base, count to 5, and plug it back in. Not the USB cord. The back of the base is convenient spot, one-hand operation.
- Plug the base in if you didn't have it plugged in and let windows install the sound driver if it wishes.
- Launch CIT300.exe. Tell skype to allow connections. Newer versions of Skype require two confirmations - one on the little pop-up and another in the events area.
- If all goes well, CIT300 will say that if found the base and all is well. Press the "Skype" button on the phone to see your contacts. It takes sometimes a minute and a few button presses to get the entire list to the phone. If are still getting "UNAVAILABLE" on the handset, you probably messed up one of the step. Close CIT300.exe, power cycle the base, exhale, and launch CIT300 again. You will probably have to adjust sound settings in Skype options to have mic and speaker go to CIT-300. Everything works just fine !
Important : Every time you restart your computer or reboot, you must do the step 3 - unplug the base power and plug in again. Unplugging USB doesn't always work. At least my CIT-300 base has some USB connection bug that requires the power cycle. I would advise against putting CIT300.exe in Startup, because you'll have to shut it down to power cycle the base anyway.