Hard drive problems

I have an Abit IC7 and recently I have been experiencing HD problems.

A few months ago one of my SATA drives died (the main one with windows on
it) so I purchased a new one which installed and ran fine.

Recently I booted the machine to find that it could not locate the OS, I
formatted the drive (well the partition with windows) and reinstalled, again
it worked fine.

Turned it on again the other day and it could find neither of my SATA drives
(both Seagate barracudas the one that died was a maxtor, never again), a few
reboots and it found them but it has not been running right since, the HD
seems to stop every so often (main windows one, I'll call it HD1) which
causes windows to stop what it is doing also, it will then carry on.

When transferring data from HD1 to my external USB 2.0 HD everything else in
windows grinds to a halt, even the mouse is jittery when moved across the
screen.

I'm pretty sure I was able to copy 100 gig from my SATA (second one, HD2) to
my USB HD in a few hours, whilst backing up 100 gig from HD1 to USB
yesterday it took nearly 12 hours.

Others have said that my SATA controller on my mobo might be dying or that
it could be the SATA cables.

I admit that I forgot the install the intel chipset drivers until yesterday
(following the OS not found reinstall mentioned above) but they have not
improved things, I used the latest ones listed on the abit website, ver
8.something.

Also on the abit website is a file (drivers) for the SATA drive but that
just contains INF files and data, right clicking and choosing install on the
INF didn't appear to do anything.

Unfortunately the IC7 is socket 478 so if I want to upgrade to something
decent I'll need, mobo, processor & graphics card which is a lot of money.

I have a new SATA & cables arriving today (Western digital) and will see if
that improves things with a fresh install of windows... does anyone have any
other suggestions on what might be wrong before I spend lots of money
replacing the motherboard?

Many thanks,

Moo

p.s. sorry for the long post.