I'm a novice GNU/Linux user. I'm looking for a GNU/Linux operating system that works well on a computer that was originally pre-installed with Windows 7.

Specifications

free (zero price)
easy to use for non-technical users
installing and uninstalling software are easy to do
wireless works normally
software in the repositories are reasonably up to date (I don't mind if the software in the repositories are not the newest version, but I don't want them to be too outdated.)
can play online Flash videos (YouTube, Metacafe, Vimeo, Dailymotion, etc.)
can play .mkv, H264, and 1080p videos without lagging
can play 3D video games without lagging (I'm talking about 3D games that are a few years old such as Half-Life 2, Bioshock, Portal, and Portal 2. I'm not planning to play the newest 3D games on this computer.)
respect the user's privacy

I don't mind if the operating system contains (or allows the user to install) some proprietary software. I can tolerate that as long as the operating system is mostly open source and doesn't spy on me.

My computer is a Toshiba Satellite L645 PSK0NL-00H001 laptop. It's only a few years old and in quite good condition. When it is running on Windows 7, it can run HD videos and 3D video games quite well, so I think the hardware is decent enough.

http://www.toshiba.co.th/2009/th/not...645_1055x.html

Most Linux distros are free.
The easiest to use, and the most recommended seems to be Mint:

http://linuxmint.com/

Give it a try. Good luck.

Hi nuxxun, you can use any linux except the enterprise ones in which you have to pay for updates.
Go with Ubuntu/Fedora (Latest Version).

With the enterprise one also you can use external free repositories.

Playing high definition videos without lagging also depends on the hardware. If you don't have a good video card, you can try a lightweight distro like Xubuntu or Linux Mint XFCE edition.

Crunchbang fits your requirements.

I have edited the first post and added more information about my hardware. You can read it if you want.

Toshiba Satellite L645 doesnt help that much, there are a lot of models. The full model number would be something like 'Satellite L645-S4059'.

That is most of the linux distros.

Very hard to quantify. But you'd probably want to avoid slackware. While its a great distro, its a bit more fiddly than a lot of distros.

Most of the linux distros are _very_ easy to install/remove software. Easier than windows by a long shot.

Pretty much hardware/driver related. You might have some issues with some wireless hardware.

Very complex. By 'up to date' do you mean 'has the newest version of software XXXXX in the repos? If so, you're going to be disappointed, the 'easy to use' dsitros are almost always a bit behind the newest version.

It wont matter that much in 95%+ of cases, and if you're using a distro that is currently supported, you will be getting security updates, even if the software is 'out of date' if you chek the version number.

Hardware and software setup dependant. But in most cases, you should get smooth 1080p playback with a current nVidia or ATI/AMD video card once you've setup hardware video decoding.

Hardware dependant again. You arent going to play 'metro- last light' on a 2000 era video card.

Depending on the hardware you have, driver status for that hardware, the game you want to play, what distro and desktop you are running you might find linux faster, or slower than windows. Generally, if its linux native, I'd expect the same or better framerates than under windows. If its windows only, you'll need to use WINE ('WINdows Emulator', or to be more accurate, 'Wine Is Not an Emulator'), and framerates will most likely be lowewr.

That knocks out ubuntu...

I'd be looking at debian 7, maybe mint 13 LTS ('long term support'). You could use debian testing- more up to date software, but you'll probably break it at some point. Or Mint 15/16, which has short support length isues. Mint 16 which was just released last month is 'end of life, out of support' in July 2014. Fedora 19/20 is also an option, they have slightly longer support lengths than non-'LTS' mint or the ubuntus mint is based off. Dont worry, mint strips out the ubuntu spyware.

http://www.toshiba.co.th/2009/th/not...645_1055x.html

I have added some more information to the first post.

Thank you everyone for your suggestions so far.

First, let's look at the games. There are Linux games, but the Windows ones you have can all be played using Wine:
http://www.winehq.org/
Luckily, you favourites are all rated platinum or gold: they behave perfectly or very well.

You also need to decide which GUI you prefer. Currently the Linuxes that are most likely to satisfy you are Mint (Cinnamon, Mate, Xfce) and PCLinuxOS (KDE, Mate). PCLinuxOS has the advantage of being rolling-release: install, keep up-dated, and never need to re-install.

Of the others mentioned, Ubuntu doesn't respect your privacy (and also practices tax-avoidance, if that troubles you); Fedora can be very experimental and leave you feeling like a lab-rat; CrunchBang is OK, but not always user-friendly.