Before you start

Please notice, only Android with firmware newer than 1.6 does support VPN.
This tutorial was made on Android 2.3.3.

Step 1

Start from home screen.

Step 2

Press "Menu" button on your device, go to "Settings".

Step 3

Go to "Wireless and network".

Step 4

Then to "VPN settings".

Step 5

Tap on "Add VPN" option.

Step 6

Then on "Add PPTP VPN".

Step 7

Configuration screen should look like this.

Step 8

Enter StrongVPN PPTP as "VPN name".

Fill full Server Address to "Set VPN server" field. (Server on screenshot is just an example - you can find your Server Address in the Customer Area.)
Use the IP addresses 8.8.8.8 and 8.8.4.4 as DNS servers

Disable the Encryption.

Warning!
PPTP VPN connection uses MPPE (Microsoft Point-to-Point Encryption) which is very unstable on Android OS.
Our only suggestion is turning the Encryption completely off. In that case your VPN traffic is not protected of course.
If you want the encrypted connection please use L2TP.

Looks like Android 2.3.7 and newer are free from that issue.
You can check this page for more details and tips.

But again we suggest: use no encryption or setup L2TP.

Step 9

Press "Menu" button, select "Save".

Step 10

Now you should see "StrongVPN PPTP" connection on the list. Tap on it.

Step 11

Authorization window will appear. Enter your "Username" (it should be like: vpn042, for example) and "Password" (both are case sensitive).
Select "Remember username".
Hint: Username and Password also can be found in the Customer Area (check here).

Press "Connect" button.