I guess the first thing I would do is clone the drive, new solid state drives are cheap as are standard drives. (Too bad you didn't do this before things went south.) Now you have something to work with that will allow you to change things and dig around in the files without fear of doing any permanent damage to existing files. The ELO drivers are readily available on the ELO web site. Depending on the size of the touch screen, they are pretty cheap. I bought an industrial quality 10.1 inch a while back for about $180 or so. There is no difference between a touch screen and a normal screen with the exception that the computer sees the touch function as a mouse, normally connected by a USB or serial cable, separate from the video cable.
If the machine program will still run it might be possible to rebuild the database. I'm not familiar with the Messer software so I can't help with that. I would connect a mouse and keyboard to the computer to work with it, makes life easier when working in Windows, touch screens generally suck for doing any serious computer work.
If the computer is dying, then you might be able to replace it with a newer computer. But this is not always possible because WinXP won't install on some of the newer computers.
The other option is to send the whole machine to me for ''storage''