I have software on my old XP machine that was originally downloaded, no disk. I use it all the time. It is no longer supported by the vendor and a download is not longer available. Is there anyway to transfer it to my new Windows 7 machine?
I would assume you're talking about Office and maybe a few games. As far as Office goes, MS isn't made up of a bunch of idiots (well I guess maybe their marketing team) so they make it close to near impossible to copy Office from one machine to another. I would suggest you just use OpenOffice or LibreOffice if you need something like Office- they are fantastic programs and I have used them before with success. Some things are moved around and you may not have 100% of the features of Office but they do their job well. As for games, unless you saved a disk image of the game disk or something you're out of luck. I believe any program that uses the Windows installer modifies your registry and makes it impossible to just drag-and-drop the program later to another PC. There are programs that don't require an installer though like Prime95 and GPU-z. If you have any programs like those you should have no problems running those on your new Windows 7 machine if they're supported.
Intellimover from Detto will probably move any software and files for you but as other's noted Win 7 may not run older software. Some will and some won't...