At home I have only my Linux box to work with.  I'm quite content with it, but I do have some DOS and older Windows apps that I like to use.  Unfortunately, by DOS floppy's are now dead (as is my floppy drive) and the MSDN DOS download is for making DOS floppies.  What I really wanted was an ISO for DOS that I could use to install on a VM.  Fortunately, I came across FreeDOS (http://www.freedos.org/)!

FreeDOS is an open source DOS implementation.  It has been around for some time, but I was pretty excited to find it,  It comes with a huge tool set (much more than I need but includes a MASM compatibale assembler, Pascal interpreter, VIM, etc.) and would have been awesome to have in the early 90s.  If you still play DOS games it's a must.

Just thought I'd share in the event that you aren't aware of this OS.

Side Note:  If you want a floppy boot images for installing Win95/Win98/NT, These guys have them: http://www.allbootdisks.com/.