Windows 7: 500 gb HD 2 TB external Drive says not enough space

ok I have 2 problems:

1. I have a 500 gb HD C and using a empty 2 TB external Drive, it gets to a point (different each time) stops and says nt enough space.

2. This stopping of backking up is annoying in itself. So I hit to restart back up and instead of it continuing whare it left of from the other BU it begins a whole new Bakup. This Time I have 2003 zipped files while the last 2 times I had like 316 on one and 988 on another.

Is this just win 7 and its back ups? I have 2 other programs I can use Nero back up and Mameo, should I reformat disk and try one o them?

Thanks 4 your help !!!

Could you post a maximized view of Disk Managment? I suspect that you might have a 100MB System Reserved partition as part of the C: drive. If this partition has insuficient space it can adversely affect the creation of backups and system images. Has to do with creation of shadow copies, temp files, etc.

Windows Backup says not enough space on external drive, but there is