I followed the instructions to uninstall drivers. In step 5 I couldn't find any of the files mentioned:
5. Open Windows Explorer and navigate to C:\\WINDOWS\\system32\\drivers and erase the file SiLib.sys and SiUSBXp.sys and DSI_SiUSBXp_3_1.sys. Depending on the version of the driver you have installed, your system may not contain all of these files.
In step 6:
Continuing in Windows Explorer, navigate to c:\\windows\\inf (note: this may be a hidden folder on your system). There will be a batch of files in there named oemXX.inf, where the XX is some number (for example oem12.inf). The number of these files and the specific number associated with each one will depend on your system. For example, the figure below shows all the oemXX.inf files highlighted on a computer:
...I found a couple higher numbered oemXX.inf files that referenced Silicon Labs and I deleted them all.
After installing the new driver, it still shows up in Device Manager as "CP210x USB Composite Device" and I still get "Ant Initialization failed" in the new version of ANTware.exe.
If I look at the properties of this device I see that the driver provider is Silicon Labs and the individual driver files are:
c:/windows/system32/drivers/slabbus.sys (v4.28, provider MCCI)
c:/windows/system32/drivers/slabwh.sys (v4.28, provider MCCI)
c:/windows/system32/drivers/slabwhnt.sys (v4.28, provider MCCI)
c:/windows/system32/slabunin.2k (v unknown, provider unknown)
c:/windows/system32/slabunin2k.exe (5.1.2600.0 built by WinDDK, provider Windows 2000 DDK Provider)
...do one or more of these need to be deleted in step 5 above?