If you have XP it's probably 32 bit. There were 64-bit varieties but all things considered it was pretty rare. 64-bit is getting more popular with Windows-7 so it's becoming more of a relevant issue.
Anyway, here's how you can check:
1. Click Start, and then click Run.
2. Type sysdm.cpl, and then click OK.
3. Click the General tab. The operating system is displayed as follows:
* For a 64-bit version operating system: Windows XP Professional x64 Edition Version < Year> appears under System.
* For a 32-bit version operating system: Windows XP Professional Version appears under System.
Note is a placeholder for a year.
...
FYI - there may be other factors at work too where the reliability of your connection is concerned. A standard serial-port is supposed to go up to 15vdc but 12vdc was the typical standard everyone seemed to settle on. Laptop (and some other machines) serial ports dropped that down to as low as 5vdc and some USB adapters can drop the voltage down to the 3vdc range. If the connections to the 195 aren't perfect it may not respond reliably with the lower voltages (not that it can't, it's just that the poor connections might not play well with the lower voltages) - at least that's what I think.
We ran the 195s in several airplanes for years doing aerial survey work. I had the GPSs wired to laptops to get GPS data and to upload routes/waypoints on a daily basis. Occasionally the 195s just wouldn't cooperate and we'd have to pull them off the mount and clean the contacts on both the GPS and the snap-on connector.
You can use CRC contact cleaner (as long as it states "plastic safe" on it) or burnish the contacts with a clean eraser then put a thin coat of CRC 2-26 on them to keep the contacts from oxidizing. It may help with the lower-voltages the USB adapters seem to be using.
