I own a vintage Macintosh SE, Model # M5011. My kids were playing around on it and accidentally deleted a bunch of files, now it won't boot up. Where can I find the correct OS program for my Mac? Thank you, D. K. McCarty

This should be a Macintosh SE FDHD (with a floppy drive for both 800K and 1.44 MB disks), but M5011 may have been used for certain earlier SE models/variants (otherwise, M5010) as well. Could you confirm that your computer is an FDHD (and/or that 1.44 MB floppies can be used)?

Macintosh SE FDHD: Technical Specifications

Macintosh SE: Technical Specifications

Which operating system version is on the hard disk?

You will need an appropriate startup floppy to begin with. Please post back with the information above, and mention any other computers that could be used for downloads or to create a disk. Any other pre-1998 Macintosh computer (model/name) with a built-in floppy drive? A Windows PC (operating system version) with a built-in or external floppy drive? A more modern Mac (operating system version) with an external USB floppy drive?

USB floppy drives are available, but generally only support 1.44 MB floppies. 800k floppies need a beige G3 or older to create floppies or write to them.