matt832,
It is highly unlikely that Active Home Pro or the "USB adapter" could have blown hardware on your computer.
From your description of increasing problems with the Firecracker software and having to replace a memory stick and video card, my best guess would be that your computer was on its way to failing to begin with.
I personally have had a very nice Gateway PC running XP suddenly fail and looking at the mother board, several of the electrolytic "can" capacitors show an obvious bulge at the top. This can also happen with similar capacitors in the computer power supply.
Doing some online research, I found out that there was a bad batch of Korean made capacitors out there that crapped up PC's and TV's that were built using them.
Personally, I'd suggest getting another computer, or some serious electronic trouble-shooting and repair of that one.
Not sure the trouble-shooting route is worth the effort though at todays computer prices.
Just my 2 cents.