When I checked drivers for HP 2400c, HP 3970, and HP 4200 for Windows Vista
on HP's website, it showed a Vista driver for 3970 but not for 4200c or 3400c.
That doesn't make sense since the 4200c model is a newer model than 3970.
Who knows what business decisions were made by HP, in deciding to
upgrade drivers for their many models of printers and scanners? HP are
not obliged to follow some law or immutable principle which says they
must release updated drivers in some chronological order; there'd by a
bunch of HP managers sitting around a table saying "we'll do this one
.... we won't do that one ... but we'll do this other one". Presumably
there is some business logic behind their decisions. But who knows??
It is a sad but real fact, that hardware manufacturers do not make money
by releasing updated drivers for old hardware.
Fortunately, as other folks have noted, it is quite likely that the XP
drivers and software will run okay on Windows Vista.
The only place you will find HP drivers for HP hardware is on the HP
website. If they don't have Vista drivers for the hardware you're
using, then no-one else will either.
If you want to find hardware which is certified to be compatible with
the version of Windows you're using, look at the Windows Hardware
Compatibility List:
http://www.microsoft.com/whdc/hcl/default.mspx
The other place you can direct your question would be to the HP Support
forums:
http://h30434.www3.hp.com/t5/Printer-All-in-One-Software-and/bd-p/Software
Sorry to sound a bit brusque, but it seems like you needed clear
guidance on this question.
Hope it helps,
Andrew