I wonder if any of you run Data Shredder on an SSD?
If so, and if it operates like a typical shredder for HDD, you can't really be sure the data is gone.
The SSD will just shuffle bits of the data around in processes called wear leveling and TRIM.
This happens on a deep hardware level. How the SSD presents the file system, the OS can't tell.
Typically a shredder will wipe data by overwriting it many times with different patterns.
On an SSD, the processes mentioned prevent this. The SSD writes each pass to a different location.
This means the data is likely still there, and you're also wearing out the SSD faster for no good reason.
You'd have to do a secure wipe to clear all data from an SSD. I doubt Avast can do a partial secure wipe.
If it does, that would be awesome. But it is unlikely. I'm not sure it is even possible.
A secure wipe will encrypt the whole drive and zero out every cell. It then looks like an empty 'new' drive.
To prevent having to reinstall everything, you could use imaging software to backup and restore.