From the top menu bar select "File" then "Select Import/Export" in the window that opens you'll have options to select from in the left pane of the window -- the "Customer List" is under Accounts Receivable, the "Vendor List" is under Accounts Payable and the "Chart of Accounts List" is under General Ledger. After you select the one you want you'll then hit the "Export" button from the menu bar, then select the "Options" tab, on this screen I recommend you check the "Include Headings" box, then select the little button with the arrowhead on it under Import/Export File to choose the location and file name, lastly you'll select the OK button the exported file will be created in .CSV format.
Tim, thanks! I spoke with my client again and I guess I had written down the wrong version of the software - he has "Peachtree Complete Accounting" version 11.00, 1996. Is this something you have knowledge of?
Tim may still support it, but I can confirm that Peachtree Complete Accounting version 11.00 with a date of 1996 would be an old DOS version. Not sure of its capability to export, but I'm sure there are consultants on the forums who might know.
Since it's Peachtree for DOS it will be harder to get data out of that than it would be with Sage 50/Peachtree for Windows. If I they have the Peachtree Data Query (PDQ) module, it can be used to export data. I think reports could also be sent to a file. If not, you can always use the Net Use command at a command prompt to redirect an LPT port to a shared Windows printer driver which is configured to print to a file. Either way the files would require a lot of clean up.
I still have an old utility that was used to convert Peachtree DOS data to files that could be imported into a new Peachtree for Windows company. It doesn't give any control over what get's exported but it would get you basic customer, vendor, and chart of accounts information in a readable file. If you would like to contact me directly I can give you a quote for exporting your data using that.