Scheduled back ups not backing up properly

I have set weekly back ups:

1. email outlook 2007 (complete: inbox/sent/drafts...) - weekly monday.
2. my business folders. - weekly monday.
3. complete c:/ image. - monthly (fourth tuesday every month).

Iam findind that backups are finishing too quick and the pc is shutting down (even when I have deselected to turn off machine after backup)

Iam finding that the file sizes for saved backups are much different sizes. Ie, my emails in outlook do not get deleted and they increase daily, so therefore filesizes for backups should be increasing in size?

I have noticed the following inconsistent file sizes:

25/12/12 - 668,351kb
4/1/13 - 5,607kb
8/1/13 - 18,004kb
15/1/13 - 11,846kb
22/1/13 - 34,588kb
23/1/13 - 3,885kb

Same inconsistencies go with my other backup for my business folders, and my complete image of c:/

Once windows loads sometimes, there is an acronis logo animating in the toolbar telling me that there was an error or the pc must restart in 30 seconds to complete, then I restart and it comes to windows blue screen saying it is updating. I have left it on that screen overnight and in the morning 8-12 hours later it is still on that screen. hdd led is flashing like the pc is working, but it never leaves that screen.

Is there a way I can test the backups without loading them on my pc?

Help please!

Thanks,

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Windows 7 64 sp2
Iam saving to an external drive on a Seagate 2tb.