Hi Henni,
good to hear that you could fix most of your problems.
But, as mentioned in "my" SSD-thread, ANYTHING can fail. A ssd the same way like an hd.
On the other hand you learned something :
1st : ONE BACKUP is at least 2 too less
2nd : One backup each month is not enough, if you WORK with your machine ( no matter if pc or keyboard ) you should do a backup at least once a week, maybe once a day

3rd : Have your hd checked ( windows scandisk or similar ) at least once a month
4th : You know, but for anyone else : Do NEVER, NEVER unplug your Audya from the pc without the "unplug hardware-device" ( I hope itīs correctly translated from the german version ) feature from windows !
5th : Better you never plug you Audya to an Apple-device

Ooops, ... I should make a backup right now ...