Yes call Gateway because they should have at least included an Emergency System Restore disk (or something along those lines) which basically has Windows along with all the proprietary software pre-packaged systems love to include. At least Compaq gave one of those silly things with their system instead of a real Windows disk Or use this as the perfect opportunity to load up Linux

As for the .txt file, if you know where you saved it to, it should still be there. Get to the folder the file is in then copy it over (to navigate from folder to folder, use the cd command). The DOS command for transferring to a floppy would be:
Copy name_of_file.txt A:\
You don't have to specify the file name after the A:\ unless you want to change it. Sorry if this is too basic