How to protect the computer?

where is the computer located? your house, if yes I don't think a "regular" user will try to work so hard and deal with mobo pins. when they turn on the PC and see the password they will either call you or just don't use it. now if you are serious about this, you can use an encryption program to protect your data.

LOL OK!

You are little bit more serious about your PC. OK you can protect your PC by following ways.
Set Hard Disk Password,
Set BIOS Password,
Use USB Flash Drive As Lock.

Okay... let's actually get down to the REAL gritty details about hard drive security........... F'in A, this one I could go on about this for hours, but I'll try to keep it concise.

First off, there are a few ways to secure data. As there has already been mentioned, you can do an encrypted flash drive, and carry it around with you. On the other hand, encrypting the entire hard disk is a much easier solution, for any computer. The only downside with an encrypted hard drive is the password is stored in your RAM; and if someone wants to break into your PC, all they have to do is keep your memory cool while they load up a special Linux distro onto your computer, and attempt to find your encryption password. Is it difficult to do? Sort of... they would have to get to the computer within a couple minutes of shutting it down (maximum), in order to have a substantial chance of not losing the password due to heat (as RAM basically "clears" itself faster when it's hot). The only way around this is to find an encryption method that stores the password on something like the CPU; but, this isn't implemented in any programs I'm currently aware of.

Will encrypting your drive slow anything down? Unless you set the encryption method to something really elaborate, you will likely never notice any lag. When I was running an encrypted drive, I never noticed a difference (even while doing music production, which can easily be more resource intensive than gaming). Is drive encryption the best option? Yes and no. It's great protection protection against your average thief; and shutting down your computer a few minutes before leaving the house will help add a layer of security by letting your RAM have a chance to stay warm and effectively wipe itself sufficiently before you leave.

Adding a BIOS password will only help if they are trying to access your data on your machine only. Using a flash drive means you have to always keep that drive in a place that is always safe, and you can't afford to lose it. Probably the best method to prevent anyone from getting to your most sensitive material would be to use a strong encryption method, with a substantially long password (over 20 characters), and upload your encrypted files to a cloud service. If you want double protection, use something like Spider Oak, which encrypts your files through your account, and you can then benefit from access to your files virtually anywhere due to it being a cloud solution. Also, if memory serves me correctly, I believe they also spread your data to various different servers; so, basically, your uploads are divided into pieces, and are then reassembled when you download a copy (similar to the idea of torrents). I could be wrong about that, but there is a cloud hosting company that does that... or there was one... I can't remember.

Going very much beyond what I've covered is really more than is really necessary. You can always give steganography a try, though. Steganography is when you hide one file inside of another; essentially, this is concealing data inside of other data, virtually eliminating the footprint of what it is you want to hide. Depending on how you do it, it's almost impossible to detect without experienced forensic work; and even then, about the only way to extract the hidden file is to reverse engineer the code. If you encrypted the hidden file, then it's practically impossible to extract the hidden file in clear text form. The only downside is you'd need to securely erase any files you've extracted, once you no longer need it readily available, to avoid someone from recovering it (ie: if they stole your hard drive). While this would mean the person who wants your data would need to be a very diligent thief, and know exactly what to look for (and we're talking about analysing files on a much deeper level than most could wrap their heads around), it's probably the most secure method for hiding data from whoever you want to hide it from. Would it stop professionals? That really depends. For black bag operations (NSA/CIA/etc. breaks in to steal your computer), you may not stand much of a chance. On the flip side, they definitely would have to spend a good amount of time to find what you are hiding, and then extract it into a readable form. If there's a black bag operation in place, then don't count on your data being secure... but you do stand a chance.

If you want the utmost security, I'd do exactly this:
- Encrypt your hard drive with a 25+ character password, using 256 bit AES encryption.
- Using your choice of steganography software, hide your sensitive data inside of whatever "cover files" you desire. If you want double protection, either use a steg software that can encrypt your hidden data, or encrypt them before hiding the files. For larger files, use a software that allows you to hide data inside of lossless music files, like WAV and FLAC audio files.
- Upload copies of your "cover files" (with the hidden data inside them) to a secure cloud server (ie: Spider Oak).
- Every time you extract a copy of a hidden file, and are ready to delete it, use a software that will "shred" or "wipe" the space where the file was stored on the hard drive. Personally, since I already use IOBit Uninstaller, I just use the "shred" function in that program; however, pick a software that you like, and stick with it.
- Be sure to do a regular cleaning on your hard drive by wiping the free space on your hard drive on a regular basis. Personally, I suggest weekly free space wipes, just in case you forget to securely delete a file you want to remain secure.

Overkill? Depends on what you want to keep secure, why, who might want it, and what that data means to you. If I ever have something I want to keep secret, that's exactly how I would do it, as of right now. If I had a spare computer to recover my lost data, I'd tell you exactly what programs I'd use, and give you all the specs to follow... but I'm short that spare computer. I haven't had that drive recovered for almost a year, and my laptop is on the fritz, so I'm stuck without much to help you with. I can see what I can do, though, if you really need the help.

If you want genuine security, it needs to be complicated. If someone wanted to bypass the security password in your BIOS, they will either find a way, or have an easy way to bypass it. If I'm not mistaken, you could (in theory) just remove the battery from the MoBo, thereby, effectively, resetting the board. But, even still, I believe you would still be able to use the drive in another computer, which defeats the whole purpose.

Setting a BIOS password is only going to deter the low level thief. If you want to have some quality security measures that make your computer truly protected, there isn't anything else I'd currently recommend. When someone rewrites hard disk encryption to no longer use RAM for storing the encryption key, then you'll have a much easier solution. Otherwise, most basic methods available are relatively easy to bypass.

There is a way you can set the BIOS to only boot with your hard disk, and then you can set a password for the BIOS... but as I mentioned, it's a flawed security measure. I'd say encrypting your drive is a much better solution, quite honestly; and that's a decently flawed method, albeit the actual hacking method is more involved than various ways you would bypass basic MoBo security measures.