* An almost 2 year old dm1z netbook
* A 13" Pavilion laptop from late 2010
* An EliteBook 8540p
* Two older Pavilion notebook, late 2006 and late 2007
And I am very happy with the quality of their machines. The EliteBook is a tank that can compare with ThinkPads in reliability. The Pavilions are sturdy and decent for consumer notebooks. The netbook is brilliant for a $400 device, and has survived multiple drops without any serious marks.
One of the Pavilion's screen broke down in warranty, and HP's support and repair service have been a painful and infuriating experience. I can say the same about any warranty claim I have tried to make as a consumer rather than a professional client (having dealt with Lenovo, Sony and HP).
I wouldn't go near this thing (shitty screen and battery life and subpar compontents for this price level), but I wouldn't say bad things about HP's products in general. Except for their printers, those are just evil.
Enough of that. Because Windows 8 uses the same kernel as Windows 7 (and Vista) with a minor .x upgrade, you should just use the 7 drivers, as they'll most likely work.
Anyway, I don't understand why you would want to "upgrade" to W8 anyway. It's not good at all unless you have a touchscreen, and the performance gains are very minimal. Just stick with 7, trust me, you'll be happier.
Lenovo have been ok for corporate support from experience - they bend over backwards for us although we occasionally get a bad rep which needs threatening a bit :)
As for HP's other products, their calculators are a bit crappy (made by chinese outfit Kinpo), their printers are shit I agree and their best line of kit (test gear), they spun off to Agilent so the HP brand wouldn't take them down.
After trying to make clear what was wrong with the machine, he told me my warranty had already expired (though my invoice was dated less than a year before that, and the EU requires consumer electronics to come with a minimum of 2 years of warranty). The issue was never resolved, and I performed the needed repairs myself.
Fine example: Sony just replaced my spare TV which was 2 years out of warranty.
As for my ThinkPad, I bought two. If this one fails, I will just get the other one out and use it whilst repairing this with bits from eBay for not much money at all.
Not an anecdote for once...
One of our clients is a large insurer who have just dumped HP due to reliability problems. They have approximately 3000 laptops in the field. The were all HP business line (EliteBook and ProBook)
Their failure rate in a year was nearly 25% for HP kit.
Moving to Lenovo, they've got a 4% failure rate now.
Now for anecdotes: I've owned two HP workstations (one PA-RISC and one Intel) and both blew up spectacularly, one HP laptop (about 10 years ago - an OmniBook) and it blew up. They stick dynamite in the damn things.
None of which proves the new device is any good.
I don't know what was wrong with your computers, but I've owned 4 HP notebooks, and all have performed spectacularly. They're built solidly and have (for the most part) good hardware-software integration. As with any OEM, there are going to be products at the high and low ends of the line, and similarly there are going to be several failing models.
With HP, I think it really is hit-or-miss. You either get a good computer, or you get a bad one. While my HPs have been good, my friend's G71 hard disk failed.
I've been wary of what I purchase from them, and how it's assembled, but it seems to have worked. Computers are computers, and the #1 thing to fail in them is the user. The #2 thing to fail is the software, and the #3 thing to fail is the hard disk. It's very rare that new PCs come out of any factory with a fried mobo or CPU.
It's just a matter of sifting through all of the junk to find the few hidden gems. HP has a problem with QC, but if you look enough, you'll find great products at even better prices.
It has happened before. I had a 32-bit ARM desktop once: http://en.wikipedia.org/wiki/Acorn_Archimedes
Absolutely shoddy machines from end to end.