i have bought a car with the riocar in it, not sure if it's mark 1 or 2, but it seems to look like mark 1 but it does have a rotary knob. i have a problem with the clock and date function which keeps jumping to different times and dates. i also have a function that on start up tells me the day, time and date but these do not match my clock in the riocar and it als jumps around. i know nothing of these machines and almost nothing about computers so an easy solution would help. i don't mind if there is a simple way to format the whole machine. please help me.

Have any pictures ? If it has a knob I can't be a mark 1.

Here is a link to the totally awesome empeg FAQ by tfabris about the clock.
Link

Also here is the FAQ link to help determine which unit you have..

Hmmm, could it be an aftermarket fascia? The newface fascias use(d) the same plain round buttons as the MkI. They're alumin(i)um, so easy to identify... here are some newface pics.

In order to 'reformat' - you can apply the disk builder image (will also remove all music), followed by a software image (as the disk builder nly partitions and formats the drive(s)). Less drastic is to just upload new software (check the About menu to see what's currently running), keeps the music but doesn't reformat the drive(s). The developer editions gives you some handy tools for troubleshooting, so go with that instead of the consumer version even if 'developer' sounds alien and scary .

Good description of the process is in the disk upgrade FAQ just skip the physical parts)