Sansa Fuze 2GB Player, I think I've killed the poor wee thing?

I was given a Fuze 2GB and started to download I-Tunes music on my MacBook laptop using KopyMac?.

It all seemed to go ok on my first try and successfully downloaded a trial music album.

On connecting back up to pc it all seemed to be going well and I closed things down and unplugged the player.

Now it will not function on powering it up but displays the following message on the Fuze Screen. 

" Not enough space for music DB. Please free 90MB. "

I think I have overloaded it, so how can I free 90MB?

I cant run the mini disc supplied with the player in my MacBook Laptop.

The Player shows up as connected but wont function.

I am unable to operate the player to delete files as the message appears then it shuts down?

Can I reformat my Player?

Help me please what have I done to the poor wee thing? 

This is a common error. I forget the fix, but someone will post it.

Put it in MSC mode and run ChkDsk