My bad. I was wrong about an important detail here. I believed Windows would not change the size of the boot partition. That was true up to Win XP, but as of Vista it WILL do that job. You already have used those tools, but it is still limiting what it does, and I'm not sure why. However, I found out recently Windows also balks at doing that sort of thing on a drive that contains the paging file, which by default is created on the C: drive. But you can run without this file system, so it is safe to temporarily remove it, then re-establish it when you are finished your changes. See if this sequence will work.
1. If necessary, use disk Management to delete the last Partition - the one you created to hold the G: drive of 34 GB. That space at the end of the drive will revert to Unallocated.
2. Get rid of the paging file. Click Start ... Control Panel ... System and choose the "Advanced" tab. In the top "Performance" section click on the "Settings" button, choose the new "Advanced" tab, then go to the "Virtual Memory" section at the bottom to click the "Change" button. (Windows buries this so you won't get here by mistake and make unwise changes!) COPY DOWN THE CURRENT SETTINGS so you can restore them later. Then click on the "No paging file" button, then "Set" and "OK". As you back out of here, Windows will give you dire warnings that a paging file system is important, and it is. But confirm that you want to do this, and you will have to reboot your machine to make it happen. The paging file system is how Windows makes big chunks of memory available when needed, so do not try to run any big applications of handle large files while you are in this state.
3. Empty the Recycle bin, and run a Disk Defrag if you think it necessary.
4. Go back into Disk Manager and try once again to Shrink your C: drive by 65 to 70 GB. It should take this off the end of the drive, leaving you with one large contiguous block of Unallocated Space around 100 GB. If it does co-operate here, you can proceed to create the new Partition to host the G: drive you want, then format it, etc. as you already know how.
5. Reboot to verify that all the drives are set up and operating OK.
6. Go back into the place where the paging file system is controlled (item 2). This time re-create the settings you had copied down and confirm your choices. Again, you will have to exit out of these tools and reboot to establish the system. IF things go as hoped, you should be where you wanted to be.
Whatever the result, post here to let us know. If this does not work, maybe somebody else can help.