Make sure no other wallets are running , if you have a backup copy of your wallet (if not make one first), then move your wallet out of the C:\Users\"username"\AppData\Roaming\Mintcoin ,
The Restart Mintcoin so it creates a new wallet and see if it still freezes or acts normal.
While it is loading don't do anything else with the PC.
If it works normally, close mintcoin, copy old wallet back , open mintcoin and run a repair on the wallet.
Also go under coin control and if you have over 200 blocks start combining them until you get down to 200 or below. Have seen someone with over 1000 block have this type of issue.