[Elecraft] K3: Firmware upgrade harder than construction...Help

[Jay]

After 10 months I decided to upgrade my firmware from the original 2.16 
since I just got the KXV3 and KRX3...Frustration!
Have a USB 2.0 to RS232 Serial adapter and have tried it in all my USB 
plugs and in Com ports 1, 2, and 4 which are shown as choices on the K3 
Utility.....The computer tells me my driver is correct, I've matched 
9600 baud with the K3 and all I ever get is a "K3 not responding" on Com 
Ports 1 and 2, and "Another app connected to" Com port 4.  I'd just 
order the CD, but that would not solve my communication from the 
computer to the K3.  What should I try next?