You talked about it being format.exe (and not format.com) and (adding a number of perfectly unneeded exclamation points) you highlighted how this was not DOS.
And sure it is a .exe (as internal format, if I am allowed the pun), but it is named format.com.
On my system (which is 32 bit and XP) if I type on command prompt:
I get an error about "format.exe is not recognized as internal or external command, operable program or batch file".
If I type EITHER of:
I see the help for FORMAT, so I am led to believe that the file is named format.com.
I will go further, stating that on my system there is no file called format.exe anywhere in PATH (and though it's still not DOS, the PATH environment variable still exists).
If you open an open document file (such as .docx or .xlsx) you will see that it is actually a .zip file (as internal format) but still it's filename is something.docx or somethingelse.xlsx.
So this is your main problem ?
Listen, I was wrong with "format.exe", that happened because I knew it's not a real ".com" file (real .com files do only exist for DOS and can't be executed with Windows 7 64bit for sure).
But because talking about less important things is easier, it seems nobody is interested in finding a solution for a real compatibility problem of imdisk.
So I will be satisfied with 100% compatibility using vfd.sys (regardless of that driver signature problem it has), which works - as I already stated here - with the original format command without problems.
Good luck for you all anyway.