Am using win7 but figured if same memory clusters are giving me grief, would try messing with virtual memory. I had forgotten since upgrading to win7 last year I've been letting windows manage my vm limit. It was set to max limit of 3gb. So changed it to max 6gb, which probably make it pick a very different sector of the hd to avoid using fragmented area. Soon as I did that, the installer stopped crashing on me.
To change your vm mgmt, at least in win7 go to Start>right click Computer or My computer then choose Properties>Advanced System Settings. Under Advanced tab hit Settings button under Performance. Then next Advanced tab hit Change in the virtual memory box. Uncheck box that says "automatically manage paging file size...". Select Custom size.
For this purpose you'd want to make your initial size & max size the same, and make it larger than what's currently allocated. Double if possible, but at least 50% larger. Recommended will usually be 50% larger anyway, so you can match that # if it is. NOTE: you have to keep in mind how much space available you have, increasing this will take more space. DOn't leave yourself with less than 1 or 2 gb total. If you have that little space try to clear some junk out before doing this. And don't go nuts with the number like more than double or triple, otherwise win might settle for using some fragmented space and end up using some of the same areas as before that were causing the problem.
Setting your vm size to a specific min/max # is an old xp trick to help performance, in this case it saved me from this damn installer crash but just forcing windows to choose a different part of my hd for vmem. At least that's my theory. Once finished, you'll need to restart for the resize to take effect.
You can switch back to automatic paging file mgmt after the downloader is done, I'm leaving mine as is incase I really do have a bad sector on my hd so hopefully doesn't use it later.
By the way, if you've had multiple attempts like I had to get the downloader to work, it might look like it hangs up at the end of teh download. It's turning the .part files into the actual install files, so give it some time. You can check the folder itself. when you refresh you can see the tome file growing to the size of the .part file. When it gets to same size, the .part file will get deleted and that piece of the install file is ready. When all 3 .part files are gone, the downloader should close on it's own after saying download is done.