Want to experience it all again? The forests of Shadowlands? Deserts (and desserts) of Fribbulus Xax? Maybe you want to be marooned on Mars? Or perhaps don't want to eat your vegetables... Yes, you would like to do that all again, but can't. You have a computer made with the parts of latest technology, and you can't run good "old" Commander Keen on it. One solution to your problem can be DosBox.
DosBox? What is it? Well, it is a program that let's you run olde DOS games on Windows, and even in other, better, operating systems! First of all, I suggest you to check out its official site. You can find it here: http://dosbox.sourceforge.net/ Click yourself to Information page to read more about it. The main thing is, that "You can "re-live" the good old days with the help of DOSBox, it can run plenty of the old classics that don't run on your new computer!" It should run Keens pretty well, and has got positive feedback from the Keen community.
After browsing the page and reading stuff, you may want to get started. Go to downloads section, and download it there. Select Windows if you have it, and so on.
Then, install it. That goes nice and quickly. There comes some manuals with is, and I suggest you to read them. I read those, but I can't remember almost anything... Well, this is simple example and only tells how to get started simple way. And you probably won't ever need more instructions than these.
Keen runs pretty well on it, and you probably love to get playing your favourite classics on your desktop. Though, too bad, it runs pretty slowly if you don't have very powerful computer. Slowly, but very smoothly. But how then? I'm not expert on it, and don't know about any super stuff on it, but here are the basic instructions how you can get your Keens running. By the way, this considers mods too, so this can be good-bye to "Unload your TSRs!" messages, if you get them, as I do.
Anyways, here's what to do... Start the program. Then... You have to do something called mounting. I can't explain what it does, but it's needed that DosBox can access to your game files, or something like that. Well, I suggest you to make a backup of the game to some place and mount as few stuff as possible, just to make sure anyting odd doesn't happen. I'm quite sure anything odd wouldn't happen, but just to be sure... Well, let's say you have taken copy of your Keen 1 folder, and would like to play it. You have placed your Keen 1 backup to drive D and to folder KEEN1. In the DosBox program (that looks like DOS), you can do the mounting and that way get to play it, quite easily. Write "mount D D:\KEEN1". Then, you can type like in DOS, "d:". It should go to that "folder". Then write "keen1", and it should start your KEEN1.EXE! Have fun! (By the way, that "D" there means the drive letter. It could also be some other, like E or C or whatever. And then you need to write the path, including drive letter. The path could also look like this; "C:\stuff\Keens\KEEN5"...)
When you have finished playing, you can quit DosBox by typing "exit".
If you will face problems, try to look at the manuals, search the internet or visit Public Commander Keen Forum and search or ask some help...