Problems with DVD RW Drive

[johnf]

I have a Sony Vaio and have been having problems with the DVD RW Drive it will not burn anything or read CD's or CD Roms but will play and recognise DVD's, I have tried various things to get it to work but no luck, I am now thinking of buying an external Dvd Rw drive powered by USB, Most seem to use USB 2.00 but I think my laptop uses 1.1 I need to know if they are backwards compatible.