Now that I have my shiny new laptop successfully dual booting, I want to access the same files from both operating systems. I see on the side menu thing (start menu? task bar?) a "Windows8_OS" icon. When I click this, it "mounts" the partition with Windows 8.1 so I can nose around in the files. I had two screenshots from my dual boot adventures previously, so I went to those files and copied one and edited it. Now I will reboot and go into Windows and see if it worked. Yes!
I want a separate data partition though and inexplicably Windows 8.1 had 400+ GB in spite of using only about 35 GB currently. I went to Adminstrative Tools>Disk Cleanup. I selected all the files it gave me and told it to clean up system files as well (the button with the adminstrator shield on it). Disk cleanup continued. It took around 5-10 minutes and then brought up the window again with more selections for cleanup. When I said okay, it asked if I wanted to permanently delete these files. Yes, I do want to delete them. Thanks. It took at least 20 minutes. Then I defragmented again. This didn't get rid of the extra space.
Some googling let me know that Windows apparently stores some critical files at the middle/end of its original partition. I followed these instructions to move the files into a smaller region. It worked without a hitch. I left about 70 GB for Windows 8.1. Unfortunately, since I did my "unallocations" at two different times (once to make space for Ubuntu and now to solve the problem of why Windows wanted 400 GB), they are not combined. The unallocated portions were separate. It appeared the easiest way to combine them would be with the linux-based disk management GParted.
I rebooted into Ubuntu and installed (using the application manager) and then opened up GParted. It looks like I need to move the Ubuntu partitions around. I did "swapoff" for the linux-swap partition, then moved it as described on the GParted site. I just did one first to make sure it worked. I rebooted twice into Windows and then once into Ubuntu to confirm everything was happy (the site suggests just doing Windows twice but I figured it was important to see if Ubuntu was happy since this was the linux swap partition I just moved).
Apparently I then needed a LiveCD version of GParted (can be done with USB too but CD seemed easier and it fit on the old CDs I have). It was a bit over 200 MB so it took a while to download on my connection. I burned this bootable CD on the lowest speed with "Verify disk after burning" checked. I then reinserted the CD and shut down my laptop and turned it on again. It didn't boot from the CD so I went to system settings, it took me through the Lenovo screen again, where I pressed F12 to choose the boot device. I picked the third one, which had CD0 and DVDRAM in the name so I figured that was the CD.
I left it to sit a bit too long on default once GParted live had loaded and it started doing things. Then the keymap screen came up as described. For the next few questions it asked me, I picked all defaults as suggested by the GParted help and then was at step 6. I moved the remaining two linux partitions (/ and /home). While I was there I right-clicked on the linux-swap file system and labeled it "Linuxswap". After those changes were applied, I took the now-continuous and contiguous unallocated space and created a new partition which I labeled Data.
Once this was all done I rebooted into both operating systems to confirm I could see the files. I ran into a bit of trouble with Windows not being able to read the Ubuntu screenshot, because it contained a colon. I renamed the file back in Ubuntu and could see it fine in Windows then.
Finally, I needed to reset the changes I made from the initial instructions on reducing the size of the Windows partition. The memory dump change wouldn't go without changing the paging file settings first. It was still giving that error after I changed the paging file, so I did the other things (except for hibernation, which I have tried to turn off everywhere anyways).
I could have saved myself all this trouble by shrinking the Windows partition more appropriately BEFORE I installed Ubuntu. Then I'd only have had to create the new partition from the one piece of unallocated space instead of moving things around. Oh well, I learned how to use GParted! Next up I'll figure out how to redirect all the default directories (My Documents, My Pictures, etc.) to the new partition and how to do the equivalent in Ubuntu.