Dear option,
AS mentioned above, you can take an image of the OS/Software/Data on to an external hard drive. You can immunize the entire contents by simply flicking off the switch to the Extn.HDD. Before performing these tasks, make sure that the virus which landed you in this situation is removed. I am not very sure whether incremental backups (where you add newly downloaded software/MS updates, etc are added to the backup you have taken) are safe, simply because a virus entry via that route may occur.Correct me if i am wrong, because i have not come across any such problem. To be absolutely sure YOU MAY NOT opt for incremental option,though it makes your Backup look like RipWan Winkle. Since your purpose is to prevent "data corruption",check the total backup in GB and then buy an extn.hdd.
I have found the free version of "Macrium Reflect" to be rock-solid in taking a backup and RESTORING it when need be!

