If you find difficult to make a strong password, here is tool called Password tools bundle that not only generates strong password but it also analyze its strength.
The Password tools bundle is a three-in-one application – It is a password analyzer (shows the "strength" of your password)
It is a complex Password Generator (generates "strong" passwords)
And it is also a Password Manager (stores passwords securely using Rijndael).
You can generate any type of passwords and store it for your account. It works on Windows 7, Vista and XP and can be downloaded free at Sourceforge.