Which is the best way to protect my laptop from intruders trying to access my files?

passwords are easy to circumvent (e.g. with any Linux LiveCD)

If you really care about your data, you should use encryption on your disk. Newer versions of windows come with encryption software loaded (e.g. http://en.wikipedia.org/wiki/BitLocker_Drive_Encry...

For older systems, you should look for a 3rd party software. There are free and paid versions, both work great.

What's your idea of "intruders"?

Those who access it from the 'Net?

The "best" is and always has been to NOT GO ON THE 'NET.

Those who access it in the home/office?

This would encompass several system settings, access protocols, password invocations, password policy, physical isolation, and more.

Access if the unit is out of your physical possession?

Whole drive encryption with bullet-proof password.

If on Windows 7, upgrade to Windows 7 Ultimate to have the ability to encrypt the system.

If on Windows 8/8.1, upgrade to Pro to encrypt as well.

You can also use 3rd party encryption software

For you to prevent intruders from accessing your file,you have to enable the password of the device..

Lock in bank vault.

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