For a HD install Kanotix is worth looking at as an alternative. I dual boot Kanotix with Windows XP on a desktop and laptop. The GUI installer on Kanotix is excellent.

What size is your D drive?

I would transfer E data to D. Convert E to FAT32 for safe file interchange between Windows and Linux (although reports on NTFS-3g suggest it is totally 'safe' - depends how conservative you are). You can then transfer the files back and use D for Linux.

A possible set-up would be to convert D to three partitions - a linux swap (say 0.5GB), kanotix (say 6GB) and separate /home (say 6GB) partition. 12.5GB is the minimum (total) for these three partitions for reasonable flexibility and future programme additions but you could get away with much less.