Originally Posted by
khh
If you'd like to reinstall windows anyway, then I agree. However, my second suggestion should work just fine.
You can shrink the E partition to 50 gigabytes or thereabout and extend the C partition to use up the now unallocated ~150 gb, then move the files from the E partition to the C partition, then delete the E partition and extend the C partition to cover the remainder of the drive.
Just keep in mind that shrinking the E partition to 50 gb will take hours, I usually do that kind of thing over night.
If you don't have a partitioning programme, I can recomend using Gparted. It can be run from a live CD (If you've got an ubuntu live CD lieing around, that'd work fine).