Audition 1.5

Hi, I'm from Holland. I use Audition 1.5 for many many years now but recently it won't do recording internal audio from an mp3 anymore, for mixing with my guitar sounds. It's OK to import an mp3 and the audio from an mp4 but just the recording part (bottom line) won't show any audio coming in... 

I contacted a Dutch National Computer Forum and they advised me to open the register editor and go to

 Computer\HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\MMDevices\Audio\Capture\{f8bee15b-1b43-4b0d-926f-b54297c0136b}\Properties

and look for every Microphone and then go back to DeviceState and then in REG_DWORD change every value 0x00000004 into 0x00000001.

I did this but unfortunately no luck wse...

How can I use my 1.5 version in WIN10 again but with recording...?

rhermes@home.nl