DOSBox

Product: DOSBox v0.74
Website: www.dosbox.com
Type: Open Source
Requirements: Windows XP/Vista/7

DOSBox emulates an Intel x86 PC, complete with sound, graphics, mouse, modem, etc., necessary for running many old DOS games that simply cannot be run on modern PCs and operating systems, such as Microsoft Windows 2000, Windows XP, Linux and FreeBSD. However, it is not restricted to running only games. In theory, any DOS application should run in DOSBox, but the emphasis has been on getting DOS games to run smoothly, which means that communication, networking and printer support are still in early developement. 

DOSBox also emulates CPU:286/386 realmode/protected mode, Directory FileSystem/XMS/EMS, Tandy/Hercules/CGA/EGA/VGA/VESA graphics, a SoundBlaster/Gravis Ultra Sound card for excellent sound compatibility with older games...

You can "re-live" the good old days with the help of DOSBox, it can run plenty of the old classics that donīt run on your new computer!