ASUS... have been building desktop computers using ton of ASUS motherboards... not exclusively.... but hundreds of them since 1992 when I started building at a busy computer shop. Have had a couple of their laptops... all good, no problems.

Lenovo... Would normally said good, and they certainly have been. Last night I read a withering review by a corporate person who blasted their support... no complaints on hardware, but cut purchasing from them altogether for the support issue.

Normally I'd rank the two similar. And the support for corporate and consumer are often different channels.

However, it tells me I would check that out before Lenovo purchase. And that's considering my long standing good feelings about ASUS.

The other factor would have been price. Given an Oranges to Oranges comparison on ASUS/Lenovo, I would anticipate the Lenovo to be more expensive. I'm not sure they have gotten over their "high" from providing the "Think Pad" laptops and Notebooks for IBM.

What a load of balderdash, Windows 8.1 out performs 7 in most, if not all, respects!
In it's native form its looks different, but you don't need to use the "Metro" interface.
The "Windows" interface is similar enough to Windows 7 that any 7 or 70 year old can learn the differences in a couple of hours.
However, if you're too darned stuck in the past to learn that's your problem.
I'm not going to get into a PC/Apple argument, they both run on the same hardware,
Apple's monitors have a slight edge, but the gap is not as wide as it used to be.
Most people compare expensive Apples with cheaper PCs, if you go for a PC that's priced as high as an Apple the only difference is the OS. So go with your PERSONAL FAVOURITE!
As far hardware is concerned, it depends on what you want to run on your new computer. If, like most of us, you aspire to the Lightroom/Photoshop combo, then you need at least ....
1. A quad core processor, Intel I7 or AMD A8.
2. A minimum 8GB RAM (more is better).
3. Dedicated 2GB graphics RAM.
4. Storage ...
a. a 1TB HDD, partitioned for..
i. for OS and programs,
ii. LR catalogue/cache,
iii. Photoshop scratch disk,
iv. Photograph storage.
b. a 512GB SSD, partitioned as i,ii,iii above,
and a 512GB HDD (external if new computer is a
laptop) for photograph storage.
5. IPS Monitor (biggest and best you can afford).
6. DVD R/W, nice to have but not essential.
7. At least one (preferably 2) external 1TB HDDs for backups.

Ran across this ad - built by private business owner (he has others)
Desktop-AMD Phenom II X6 2.8 GH 6 core processor
8GB Ram
PCI-E powered graphics-500GB Radeon HD 6950 (hope I got it right) (100 watts just for graphics)
550 watts-dual 12V layer (whatever that is)to prevent burnout.
500GB SATA 7200 RPM
Win 7 and MS Office 2003 loaded.
What say ye photo / puter nerds! Good enough, more or different?
It's listed as a "Gaming" computer. $590. No keyboard or monitor. 3 month service for problems included.

You really ought to have an Intel i5 or i7, not AMD.

8GB of RAM memory is "ok" but not gamer level today. A gaming machine would have 16GB of RAM. You should too for that matter.

Graphics card should have 1.5+GB, there is no 500GB graphic card that I'm aware of. It likely has .5 (point 5)GB which is 1/2 of a GB. My 4 year old Dell has 1GB so that's lame.

550 watt power supply is no big deal. Most anything you're going to do in photography doesn't need that much power so it's like tell you that your car has 500 horsepower available but you do all downtown city driving.

500GB hard drive is not big. Most all computers come with at least 2X that much and usually 3X that much (1TB or 1.5TB).

You could do much better for that price. Look at Acer computers at TigerDirect.