Dos mode with W ME

Hi,
I need to find a file on a hard drive that a support guy from a proprietary software company tells the client will restore data that was somehow deleted during an upgrade process that they instructed her to do. The client tells me over the phone that the boot disk they made from W ME will not see the c drive once it boots. The ME start up disk I have will let me see and have access to the C: drive on my ME machine in my shop. Is there another way to get into dos mode in ME if my disk does not work on their machine.
Thanks