mysqldump problem

[VenuGopal Papasani]

hi all,
  I have got a problem with mysql and i want to uninstall it and then
re-install it but the problem is how to recover my data.My mysqldump command
is not working.Can i have any other procedure to recover my data like
copying the folder of my database from the data folder and then making a
backup.But when i tried i m getting the following error as *
databasename.tablename doesn't exist*

    Can anyone give me the solution asap.

Thanks and regards,
venu