i am a new one. i wan to know. how to play DOS games. on win 7 64 Bit.
Be for I buy some game

Thank

There is a Dos Emulator called DosBox. The games here on GoG already are configured to run smoothly on Win 7.

DOS games on GOG come pre-packaged with DOSBox, an emulator which allows you to run DOS games in Windows.
All you have to do is download the game and run the installer, GOG has already done the rest for you.

What Smannesman^ said. I would also add that the non-DOS games are usually worked on to work on newer systems as well . I never had a game here that didn't work, so buy in confidence :)

The only non-straightforward part is mounting a drive (perhaps the process has been simplified in newer versions?)

Suppose you want to play Commander Keen 1. Download the zip from somewhere like abandonware and extract in, say, c:\Oldgames\keen1. Then when you run dosbox a dos window will open. Then type in

mount c "C:\Oldgames" (press enter)
c: (press enter)
c:\keen1 (press enter)

You will then be in the keen1 directory through dosbox. All that remains is to run the executable (in some games you might have to run a setup exectable first). Most likely, you'll have to type:

keen (press enter)

To see a list of files simply enter "dir" which will list them, after which you can simply enter the name of the executable you wish to run. Note though that this is the long winded approach and there are many cool shortcuts and programs i believe you can use to make running games through dosbox effectively painless. I would suggest you look up some dosbox tutorials on youtube.

edit: o ok i notice now you are referring to games that you want to buy on this site. In that case you dont have to worry about what I said :P The games on here that require dosbox do the above bit automatically. What I said is only relevant for the plethora of other dos games that you might want to manually run through dosbox.

Some of the free games are dos games , Dragonsphere; the ultima games, lure of the temptress , for instance will let you test whether dos(boxed) games work on your system.

My experience with Dosbox, on Gog or with older games I happen to own, shows that there are very few issues. Some games might want you to install nglide (another emulation layer that emulates voodoo graphics, usefull for red baron and dungeon keeper 2 ).