1 very few maybe only Medion nowadays
2. yes just format the c: drive the partition with the backup of the drive is usually hidden.
if you do a factory restore it efectively formats the drive.
3. Not often you usualy have an 1 chance option to burn your own when you first start up.
Best bet is to use Acronis True Image to copy the drive then you have a backup if the drive fails or you want to renew the drive for a bigger one.