I installed DOSBox a couple of days ago and after becoming familiar with how it works I had it working beautifully, loading up GW BASIC and from there the program I wished to use. Then Windows 10 installed an update and following that, the next time I tried to boot up I got a "Cortana cannot open" message. After several attempts I closed down illegally, turning off at the wall. Next boot the computer worked fine again and has done since.... except that DOSBox now won't open GW BASIC.

I have the GW BASIC program, ("b.exe"), and some GW BASIC programs I wrote many years ago but still wish to use, along with their data files in my D partition in a folder called "homeacc".
At the z:\> prompt I enter "mount c d:\homeacc" and that works OK. Then at the resulting Z:\> prompt I type "c:\" and get the resulting C:\> prompt. I then type "b.exe" which used to open GW BASIC ready to go, but now I get one of three results. These are, in order of frequency:
1) The cursor goes down a line; sometimes it is flashing and sometimes not, but either way I can do nothing with it. The only option is to manually close DOSBox.
2) Nothing happens at all when I hit <Enter>, and after a few seconds DOSBox closes itself.
3) I get the C:\ prompt again. It will then accept a small number of DOS commands, DIR for example brings up the directory, but that is all. If I insert b.exe again, or any BASIC program in my homeacc folder it results in an error message.

Would love some help please.

Bill in OZ.
OS Windows 10, Browser Firefox, AV Avast Pro, Malwarebytes, plenty of memory and disk space