My windows program doesn't work correctly in parallels.

I have a disk manager program that is used specifically for embroidery designs to be copied on a floppy disk so it can be used in an embroidery machine.
The program should read and write to the disk. In parallels, I could only copy & paste files to the open program.
It would not read a disk nor would it write to the disk. In fact, once I pasted the designs, I could not start a new page.
I have never had this issue with a pc.
I'm using Parallels 9 and Mac Yosemite.
Is there a solution to this issue?

Thanks

 

I'm going to have to make some assumptions due to the lack of information.
Recent Macs don't have floppy disk drives built-in, so I'm going to assume the fd drive is an external USB one.
If your program accesses the fd in a standard way then it can be left out of the equation, what's important is that Windows (I 'll assume the Guest OS is Windows, knowing the version would also be helpful, I'll just assume it's XP or later) File Explorer can see and navigate the disk, if it can your program will also.
Considering all these assumptions I assume the problem is is that you did not assigned/attached the USB fd drive to the VM, when you plug in the fd while running the VM you should get a window asking where do you want to attach it to, you should pick the Windows VM.

Read this:
http://download.parallels.com/desktop/v9/ga/docs/en_US/Parallels Desktop User's Guide/32916.htm

If you still have problems, try this:
http://kb.parallels.com/111725

If this does not address your problem than you should provide much more information, screenshots, error messages, etc.