Sorry folks, just got frustrated the other night. I know to troubleshoot but I only had one cable in the shop. It worked before but did not the other night.
One of my DTU4's has a mini USB (used for Mobius and GoPro cameras) and the other had a micro usb.
On a WinXP ThinkPad it recognized the one with the mirco USB, no problem. The USB driver was already in Windows XP.
Some of the mini USB's have a different pin arrangement where Mobious warned it could damage the camera.
(I have not had one damaged but some of the mini cables will not connect to the Mobius.)
I swapped to another USB mini cable now both work.
I also have an original serial port download cable from the miniAlt days. Perfectlite says it will work with the new Stratologgers and Pnut. I have acquired several used laptops from folks at work. Older WinXP laptops work great for downloading flights and video files. Some have a COM port and all have plenty of USB ports.
As far as recognizing which com port to use is easy.
Run DataCap program and select the com port utility.
See which come ports are active.
Insert the usb cable connected to the DTU4, (do not plug into the altimeter yet)
Then click on rescan again, the newest port that shows is the one to select for the DataCap program.
I should have done more troubleshooting before I posted....