XP Home or Pro Backup size varies

Using the boot CD and build 903 with XP Home, the full backup using high compression is 4.54 gb. TI reports before the backup it is 3.4 gb.
Upgraded the PC from XP Home to XP Pro and the same backup has now
reduced to 3.9 gb which will fit on 1 DVD.
Is there any reason why the backup for XP Home is larger than XP Pro?
These results were taken immediately before and after the Upgrade.
Peter

 

Hello Peter,

Thank you for choosing Acronis Disk Backup Software.

The difference may be resulted from the fact that the data on the disk has changed. It is very difficult to tell what is really changing during the upgrade to Windows XP Pro and what files become smaller or bigger, etc. I don't think there is somehting wrong in your case anyway. To be absolutely sure you may verify the new image using "Check Image" tool.

Thank you.
--
Ilya Toytman

 

The one thing i found that seems to be mainly responsible for increasing sizes of Images is System Restore. Flushing the SR points can reduce my image size by 3-4 Gb!!

Perhaps all your old SR points have been cleared out??

 

Not if everything is equal, but since this is right after an upgrade, here are some possible differences that would explain why the Pro upgrade backup would be smaller:

1. All old System Restore points are deleted during the upgrade (noted by PaulB2005)

2. Windows Updates may be deleted. These can be quite large, especially if the original XP Home was upgraded to SP2.

3. Change of disk format from FAT32 to NTFS.

 

Thank you all for the info.
In both cases System Restore was turned off, however XP Home was updated
from Sp1a to SP2.
Restored to XP Home again and checked, the file size is 4.54 gb.
Restored to XP Pro and file size is 4.11 gb.
Like to keep master backup on one Bootable DVD which now can be done with XP Pro and use a USB HD for weekly backups.
Peter