It's not a desk PC, which is placed at home or office where the access is limited, laptop is a portable device, which is easier to lost and it can be stolen. So, it's a good idea to think about proactive security measures that can be performed to prevent security accidents.

First, I prefer to keep important data on encrypted disks, there are a number of software programs that helps to do it. The most well-know tools are PGP and TrueCrypt. The last is open source product and can be used for free.

Second, if I delete some file I want it to be irrecoverable, that's why I'm running file shredder which stays in background and wipes all files that I delete. Also, as additional measure I managed to run wipe free space in the end of every week.

Third, password and login information. It is probably the most valuable one, so I prefer not to use auto fill option in browser and type the passwords every time I need to log in, it's a simple rule and I don't waste a lot of time doing this.

So here are my tree rules, there are some minor ones. For instance, the probability that someone will steal your laptop is much lower that probability of data lost due to system crash, so it's really important to do a backup every time you fill it's necessary. It's a good idea to do a backup every month or every two weeks.

There are some kind of software, that will monitor the health of your system. It's worth paying attention to SMART hard drive technology, it gathers the valuable information about your hard disk health and share it with you, giving you an estimates about how long you will be able to use your hard disk. I'm sure your laptop already have some software that will represent you this information, but there are also, some nice third-party tools.

Pay attention to your firewall and web-browser. Installing a good firewall software or just configuring firewall software suggested by latest version of Windows, will help you to protect laptop against spyware software. Don't forget to clear browser history and cache from time to time, as it also might contain a valuable information about your traces online.

Some other security measures, that might work. Flash drivers can be used now as a keys to your laptop. For instance, you will not be able to log into the Windows unless your flash drive is inserted. Well, this is for sure, a kind of protection, but there are a number of ways to get information without starting Windows, so you need a real protection, then USB flash drive key should contain not the password for a Windows login, but the key which is used to encrypted the whole data on your hard disk.

But again, before using strong protection consider checking the possibility of corruption of encrypted volume. It's much more harder to recover corrupted encrypted volume, than just a hard disk with non-encrypted FAT system. So, the main rule about security is to do enough to protect yourself and not to try to do more.