1-So long as the operating system & it's files are on C then D is irrelevant tho it would be good to create 1 file/partition image of D to save time; tho it won't need to be restored at the same time as C;only time you need to restore D is if something happens to D say a virus or corruption
2-You MUST get an external hard drive even if it's only 1; as you will NOT be able to restore from the same physical hard drive if both the OS (Operating System) & back up image are on the same single whole hdd regardless if partitioned or not
3-Forgot to mention last post,you can reduce overall image size if before hand you disable temporarily the pagefile (will require reboot) after which do a defrag then create a backup image; it will be necessary not to use any other programs while creating an image;would most probably pay to set the imaging program to low priority in case not enough ram is an issue,you maybe able to this from the task manger before executing a backup
4-ALWAYS create single system image files for C,or file/partition images if you want to backup C&D at the same time;as using differential & the other one i can't think of at the mo are extremely prone to corruption
