Here we will take Samsung Galaxy smartphone as example, and provide some tips for you to connect Samsung Galaxy to PC.
How to Contect Samsung Phone to Computer
Preparation: Before connecting to computer, uncheck "USB debugging". (You can go to "Settings" > "Applications" > "Development" > "USB debugging")
Step 1 Go to "Settings" and choose "Wireless and networks", then, click into "USB utilities".
Step 2 Tap on "Connect storage to PC" (when your phone is not connected to PC). Then, it will pop up a window telling you to connect USB cable to use mass storage. Do not click "Cancel" now.
Step 3 Connect your phone to PC with a USB cable, and press "Connect USB storage" on your phone when it reminds USB is connected.
Notes: The above operation is workable for Android 2.3 and may vary from devices running differernt Android system versions.
If you are using Samsung Galaxy S6/S5/S4/S3 running Android 4.0 or above, you just need to go the settings and switch on USB debugging. Then, connect your device to the computer.
Hopefully these tips can be helpful for you when connecting your Samsung Galaxy to computer.