Try logging in to phpMyAdmin using the user
pma usually with no password.
If you have the privelges with
pma try and create the root user again from the
Priveleges menu in phpMyAdmin.
Also I found this from a Google search:
http://www.experts-exchange.com/Databas ... 54667.html
I did not test it but you might care to if the pma is not successful.
If it works for you then post back here so others might benefit also.
If all else fails then the general consensus is to re-install.