CreateFile("COM" + 1->255) as suggested by Wael Dalloul
✔ Found com0com ports, took 234ms.

QueryDosDevice()
✔ Found com0com ports, took 0ms.

GetDefaultCommConfig("COM" + 1->255)
✔ Found com0com ports, took 235ms.

"SetupAPI1" using calls to SETUPAPI.DLL
✔ Found com0com ports, also reported "friendly names", took 15ms.

"SetupAPI2" using calls to SETUPAPI.DLL
✘ Did not find com0com ports, reported "friendly names", took 32ms.

EnumPorts()
✘ Reported some non-COM ports, did not find com0com ports, took 15ms.

Using WMI calls
✔ Found com0com ports, also reported "friendly names", took 47ms.

COM Database using calls to MSPORTS.DLL
✔/✘ Reported some non-COM ports, found com0com ports, took 16ms.

Iterate over registry key HKEY_LOCAL_MACHINE\HARDWARE\DEVICEMAP\SERIALCOMM
✔ Found com0com ports, took 0ms.