I have a couple of problems with Windows Vista Home Premium that have both
been getting worse and more frequent:

* system freezes / crashes - the error reports suggest a problem with
networking hardware, but the drivers seem to be completely up to date. One
of the "solutions" did make reference to Vista having problems with older
networking hardware, but wasn't clear on how to diagnose this, or tell which
hardware gives a problem. My ADSL modem is quite old, so may be part of the
problem - details below.

* file downloads stop part way through - doesn't crash or give an error
message, just stops saving any more data so the download process nevers ends
(or gets timed out, depending on the application). I first noticed this as a
problem with Windows Update, specifically the Windows Mail Junk email filter
wouldn't download. The error report number was 800B0100, this suggested
downloading the CheckSUR tool. I tried to download this tool, but couldn't
do this due to the problem with downloading described above. The same
problem with downloading files has since appeared with downloading files from
other sites eg software for a Nokia phone, video and audio files on YouTube,
BBC etc. Most recently, it has started affecting my Kaspersky AV - the
updates get timed out so the AV is increasingly out of date.

I'm not a very technical person so if replies could be pitched at your
average dumb user I'd be very grateful.

System details:
Dell XPS M1330
BIOS version Dell Inc. A12, 08/07/2008
Vista 32 bit Home Premium, Version 6.0.6001 SP1 (SP2 update failed due to
the downloading problem, but individual updates have been kept up to date
apart from the Windows Mail one)
Kaspersky Internet Security 2009 (Windows Firewall turned off as recommended
to stop conflicts)
MS Office 2007 Professional (so using Outlook rather than Windows Mail)
Network adapter: Broadcom NetLink Fast Ethernet (type 802.3)
ADSL modem: ASUS AAM6000EV (about 7 or 8 years old) plus a little 8 port
hub, both been working fine forever