Here is a list of links you might find useful
Items in this list are not permanent and may be added and removed as I see fit.
WinWorldPC: For all your (probably illegal) Windows virtual machine needs. Old software, old OSes, patches and fixes and almost everything you need to get your Windows VM going. Unfortunately software after and including Windows XP is generally not available because Windows XP is still deemed "competitive" by Microsoft.
Archive.org: Known by most for the Wayback Machine, Archive.org also has a great and large collection of old software and other media. If you can't' find it on WinWorldPC you might find it here, tho you wont always have a serial key or crack for the software uploaded for piracy reasons.