What gaming desktop should I buy?

I have a pretty good budget coming in with around 700-800$. I have been using an alienware laptop for the best two years and a half and thought that I should really step up my gaming with a new PC. I'm very confused on what to get though. I want a computer where I can play games, not overheat, and multitask at the same time. I have been looking at the Lenovo - Erazer X315 Desktop - AMD A10-Series - 12GB Memory - 2TB Hard Drive - Black and was wondering if this was even a good CPU. I have no idea what to do and any help would be appreciated.

How to configure an Operating system with my PC?

I got a Lenovo Thinkpad T61 without an operating system, and without a recovery partition intact. I also did not have a Windows Vista OS disc, which is what the T61 runs on, so I got myself a set of Windows 7 Home Premium recovery discs I made from my desktop, and used that instead. Now the computer works, but I have a few issues:

1. The T61 now thinks it's an Acer computer with all the Acer files and all that, so basically right now this is an Acer computer inside a Lenovo machine.

2. System doesn't run properly (things crash regularly, webpages don't open, lags everytime I try to click anything, even windows explorer)

My hoped result is to have a real Thinkpad computer that works like a Thinkpad with Thinkpad files and drivers on it, not a Thinkpad computer with a bunch of Acer on it. Any fixes?

Lenovo z50 preinstalled webcam software?

Lenovo z50 preinstalled webcam software?

Added (1). i got my lenovo z50-70 today in the mail, unlike my last laptop which was HP that had an obvious preinstalled Youcam for the webcam, i can't find anything on my desktop or programs to use my laptops webcam. Should i download free software like manycam or something?

Think centre m91p - keep usb power on?

I have a Lenovo thincentre m92p desktop, but I can't seem to turn the Ian powers on when I turn the computer off.
I tried the bios and the windows device manager but to no avail.

What power supply would be compatible?

I been looking to upgrade my desktop with a new graphics card and need a new power supply i have a Lenovo TS140 ThinkServer i3 core was looking somewhere around 400-480 watt s i'm aware i'm going to need a 24 to 14 pin adapter but i wan t to make sure i don't wind up giving something to much power.

Laptop or desktop for gaming?

Laptop or desktop
my brothers are currently building on our house so it is likely that electricity could be disabled that actually happened 3-5 times but rarely happen and i don't like that so in this case a laptop will help

but the desktop could be upgraded later and so much cheaper

as for buying it
first of all i don't trust websites ok? Don't give me links
and i'm afraid i will be stuck with half of the parts and not able to find others

my budget is $2600
keep in mind shops might take more than the parts

simply a desktop or laptop

MAKE SURE YOU READ All OF THE ABOVE OR YOUR ANSWER IS POINTLESS AND WON'T Help AT ALL

Added (1). there was no need for earning points spam

if you have something to say just say it if you don't why say something will not help at all to give yourself a few points?

and as for the afraid of not being able to get all the parts as i said i'm going to find parts in shop by shop near me

My Wi-Fi keeps disconnecting me on my computer?

I have a Lenovo Thinkpad, and this has been like this ever since I got it. My home internet is a good Wi-Fi. There's literally no problems with it whatsoever. My iPhone connects fine to the Wi-Fi, and so does my desktop. But on my computer, this Wi-Fi keeps disconnecting. I have to manually go back into connections and reset it. It is super tedious and annoying. You don't know how many times I was uploading a YouTube video and my Wi-Fi just crashes. I really can't use my computer anymore. Please, I beg of someone to help me fix my computer.

What PSU and GPU do I need for this PC?

I got this bought for me from my parents: http://www.ebay.co.uk/...1294273175, its a mini PC so unfortunetly they are horrible to customise. I want to play my steam games on it, like CS: GO and GTA V. I'm wanting a graphics card that will fit the mini case (preferably a 3GB or 4GB card, i'm aware it will bottleneck because my cpu is only 2.4ghz), and i'm presuming ill also need a new psu, which will also have to fit. I've already ugraded the ram, do you guys know any graphics cards or psus that will fit that are cheap as possible (i'm pretty broke)