Windows Backup is double the size

Windows Backup worked fine for me for 1.5 years. Now something strange is happening.

I have it set to do a weekly backup of data files. I noticed a week or so ago that the backup file size was 180Gb instead of 90GB. Looking at the backup it said something like 7/22/2012 to 8/12/2012. Prior to that last backup it had been working fine and the size was about 90GB.

So I erased that backup and did a new one on 8/17. Its size was 93GB. Yesterday after it's weekly backup which should have only added new files the size is now 186GB. It is labelled 8/17/2012 to 8/24/2012.

Looking at the backup I don't see duplicates of folders/files so I don't know where the extra complete backup even is.

Why is this happening? How do I get it to work properly?

You don't really say what type of backup you are doing, but I suppose two things to look for, are you backing up the backup or doing full backups instead of changed file backups?

Something may have changed your settings or preferences.

This is file backups through Windows Backup and Restore. Not a System Image.

As I said it worked fine for over a year. It's set to backup every Friday. After the initial backup, each week it would just add new files.

The backups would look something like:

8/28/2012 to X/XX/2012. The first week it would be 90GB in size, the next week it would be 90.5GB. It would increase slightly with each new weeks date.

The last few times it would show the date format but instead of 90.5GB it showed 181GB.

Someone said maybe I am doing a backup of the backup. I don't see how. Here are my settings. After this problem I changed it to backup My Libraries only instead of Administrators also (which I am) but it still doubled the backup.

ReviverSoft said:

On a side note, I would recommend using a better, third-party backup or imaging program on your PC.

OK I give in. Not sure why things changed but Windows Backup & Restore is not working properly. Perhaps it's related to the new Network I created and the fact that Windows Media Player sharing service is enabled, I did read some posts about this.

Regardless it's time to move on. My goal is to back up files. System Images are not a priority.

My Seagate external drive has it's own backup utility and I used my old Maxtor's built in software with success. Does the Seagate backup seem like a good option?

Macrium seems geared toward images and frankly the whole creating of disks has me confused.

As I said all I want to do is backup my files, documents, music and pictures. And of course be able to restore them easily to either my current or a new computer if necessary.