Okay, thanks. Clearly an issue here. Bug Logged.
Beta 1.7 also crashed on my WinXP system when I tried "checking for updates from the 1.7 menu.
I then tried your work-around
(going to C:\Program Files\Scrivener\liveupdates\autoupdate-windows.exe) ,
and it worked PERFECTLY
Thanks! 
Marta
RE: “I’m sure this is not how it’s supposed to work, but I had to manually start the program autoupdate-windows.exe found here:
C:\Program Files\Scrivener\liveupdates”
It works.
Same for me.
Thanks for this great trick !
The function available in the help menu only caused the application to crash when I closed the dialog."
I’m running XP SP3 as admin, and I don’t get the download button. I don’t crash, which is not a bad thing 
Haven’t tried it on my XP system or Vista system, but on the laptop I just got (Windows 7), when I go through the menu to the update, I get one window that shows the same as what Wolfman has in the image up above. Tells me that there is an update available, but no offer to get it. No crashes, either.
Going through the route the OP explained, got a wizard with multiple screens, and it worked and updated. Scrivener was open at the time. Didn’t ask or tell me to close it, didn’t crash, but didn’t show as updated until after I closed and reopened. (Which would seem like normal behavior… was surprised, though, that it didn’t force me close it.)