How do I unlock my laptop when I've forgotten my password?

Hello, I have been experiencing a problem with my laptop. I seem to have forgotten my laptop's password and now I need to unlock it. I have a lot of data on it and cannot afford to lose it by formatting the system. My laptop’s configuration is as follows: Intel Core i7 – 720 QM processor, 4GB of RAM (2 x 2GB each), a PCI express graphics card with 1GB of DDR5 RAM and the operating system installed is Windows 7 Home Premium Edition. Please help me unlock the password (just as we could do the same in Windows XP). And also, can you please suggest a good antivirus utility in the budget of Rs 1,000? Presently, I am using Microsoft Security Essentials. Thank you in advance. Click here for full story