I need a new desktop & a new laptop. Desktop is easy - Dell. I've used them for more than 15 years and am reasonably happy. HP has a really slim 12" screen laptop that doesn't have an internal CD drive which appeals to me a lot.
So, what do I need to look for (and look out for) in terms of specs for a Windows 7 machine? (I skipped Vista entirely and have no regrets in that department.)
Minimum processor speed?
Pretty much any new processor will be fine. Bleeding edge isn't needed (unlike when Vista came out and demanded near that.)
Minimum bus speed?
The faster the better if you are interested in speed. 533Mhz should be fine though.
Is a "dual core" processor essential?
Not necessarily, but it don't hurt either. It's getting harder to find single-core CPUs in new machines too.
Is 4 gig of RAM silly? (my first PC had 64K so I have problems with this)
Now days, not so silly, especially if you are going to have those apps all opened at the same time. (My first REAL computer had 16K and upgraded to 64K as soon as I could, so I know the feeling.) Most apps now days are bloatware, not only in features, but in required memory and disk space... they get optimized for CPU speed at most, and rarely ever optimized for space (as CPU designs like equal size chunks to read into memory and not have to fuss over "odd" sizes. ) They also rarely have the best code to do a task (compilers and programmers at fault there) as most programming houses are interested in spitting out apps as fast as possible instead of the best possible.
Any special video and/or audio ports I should have? Video driver specs?
If all you are going to do is run business apps, almost any card will work. Just try to avoid "shared memory" video as it steals system memory, and because of this is slower. If you need to use 3D CAD or other graphics intensive software... well... the more card the better. As far as video drivers, Most out there will be good. DX9 is a min with Vista, I suppose it to be the same with Win7. I doubt you'll find anything less than DX10 cards now.
I'm assuming that a 7,200 rpm hard drive with 160GB is a bare minimum for the desktop. 320GB more reasonable.
Get as much of this as you can afford, you'd be surprised how fast you can run out of space, especially when dealing with many business documents. 7200RPM is good, 10000RPM could be better, but is more expensive, and heats up even more. SATA is the current way to go.
Oh, and what's the "standard" aspect ratio for monitors now? I can't remember when I bought this one, but it's more square than anything I've seen at the stores (which have zero technical staff BTW).
Well, from what I see, the 16:9 aspect ratio "widescreen" is pretty much the norm now, but if you're satisfied with an old 4:3 aspect ratio ("regular old TV") monitor you already have, by all means go ahead and use it. If you are going to watch movies on it too, might as well go the 16:9 aspect ratio though.
Best advice, buy the most you can afford, focus on memory, hard drive space, Buss Speed, and CPU speed for biz apps (in that order.) Gamer focus is a little different.
As a side note, HP laptops don't have a great reliability record. (Acer is the Packard-Bell now days.) The highest reliability rated laptops seem to belong to Asus and Toshiba.