Ardin,
Sounds like you're suffering from corrupted tables. This can happen on Win32 if MySQL isn't shutdown properly. Try making a back-up copy of your data directory, un-installing MySQL, re-installing MySQL and copying your back-up data directory into the new installation. If MySQL still doesn't start, you've found your problem.
If that is the problem, it's most likely that the mysql table itself was corrupted. You may be able to recover the rest of your tables, but you'll have to recreate all your user accounts and their permissions. HTH.
Geoff A. Virgo