There are MANY other options. One is the spreadsheety Gnumeric. Its statistical functions are much superior to Excel or Open Office so that is one reason I like it (as a statistics teacher). It is also smaller and ligher than OO and just a spreadsheet so there is no need to install an entire office suite. I just opened an old AsEasyAs file with Gnumeric in Linux so presumably you could do so with Gnumeric for Windows.
My old WKS files I now use mainly with Lotus 1-2-3 for Windows Version 5 running in DOSBOX on Linux as well as Windows 3.1, 98SE, 2000 and XP. DOSBOX will run Windows 3.1 plus most Windows 3.1 or DOS programs in Linux. Linux and DOSBOX are free. DOSBOX also runs in recent versions of Windows where folks use it to play old DOS games, but you might be able to use it to run AsEasyAs or 1-2-3 in recent versions of Windows. You can buy old versions of 1-2-3 for peanuts on eBay as part of Lotus SmartSuite. I personally did not like the versions of 1-2-3 after 5 which means SmartSuite 4 or earlier, but your mileage may vary.
Another option is to multi-boot your computer. I have a number set up to boot DOS (with Windows 3.1) plus a later Windows plus one or more versions of Linux/Unix. Or you could run a vitual DOS or Windows machine in the OS of your choice.
Another is to batch convert your old files to Excel format or anything else that can be read today. There used to be several batch file conversion programs out there that not only converted the files but would do a whole directory full at once. Adobe Acrobat 4 included Word for Word, Corel Office 7 included Quick View Plus, and Outside In was another such product. Most of these are history today but you can often find old software for cheap on eBay. Of course you would need a platform that runs it!-) I made Excel version of all my WKS files in 2009 though so far I have been able to use the originals via one or more of the methods above.