>>925
KBより
http://www.acronis.com/homecomputing/support/kb/?aid=871

User’s Guideにも記載されています。

2.4 Upgrading Acronis True Image Home

If you already have Acronis True Image Home installed, the new version will simply update
it; there is no need to remove the old version and reinstall the software.

Please keep in mind that the backups created by the later program version may be
incompatible with the previous program versions, so if you roll back Acronis True Image
Home to an older version, you likely will have to re-create the archives using the older
version. We strongly recommend that you create new bootable media after each Acronis
True Image Home upgrade.