- Go to Menu > Settings > Application > Manage Applications> Play Store.
- Therein, you can see the Clear Cache, and Clear Data options. Click on both of them respectively.
- Head back to the home, and reboot your phone.
The error 120 in your Android may have been solved by now, but in case it hasn’t, and also if your phone is so old that it doesn’t support the Play Store App, you can install the apps manually,