Windows 8.1 Single Language Backup

Hi All,

I recently bought a Dell Laptop with following OS: 

• Windows 8.1 Single Language (64Bit) English

The technician at Dell authorized store says that the backup can be taken only on USB drive and not on CD or DVD. He say that when he is trying to take backup, system triggers a message to insert the USB drive and CD or DVD is not readable.

Is it rights? OS back can be taken only on pen drive?

Regards,

Ashutosh