You have several options available, with a virtual machine probably being the most reliable (as posted above). If you can somehow get hold of a Win95/98 installation disk, you can run it inside VirtualBox or something similar.
Another (far easier) option is to check out GOG.com for re-releases of any old games you may want to play. They have all been optimized to work in modern versions of Windows. You may have to pay for them again but you also get lots of goodies such as manuals, music and behind-the-scenes extras, so it's well worth it.