You have to reconfigure MySQL Server. for that follow these steps.

1) Open mysql intsaller.

2) Click on Reconfigure (to the left mysql server)

3) Go to Authentication method tab (by clicking on Next twice.)

4) Then select the radio button Use Legacy Authentication Method. Click Next.

5) Enter your password. Click on Check. Go to Apply Configuration (by clicking on Next twice).

6) Click on Execute. Then Finish.