Well...got it all together again.
Disabled virus checking and defragging on the 'iffy' drive to minimise head 'work', and partitioned the drive into 4 so that if the problem is specific to one area of the disk surface the other partitions 'should' be OK....unless the boot sector fries or there's a full mechanical failure...
Outlook was 'frustrating'. I tried the Scanpst.exe file to see if the pst was damaged...it wasn't, so I backed it up and deleted its normal position.
That didn't work...still crashed.
Uninstalled Office 2k and reinstalled.
That didn't work...still crashed.
Scratched my head some more.
That didn't work...still crashed.
Got desperate and deleted the files from...
C:\Documents and Settings\Paul Martin\Application Data\Microsoft\Outlook\
And from...
C:\Documents and Settings\Paul Martin\Local Settings\Application Data\Microsoft\Outlook\
And, presto...it loaded.
And asked for the pst location...I pointed to it and all was well again...

It was the other folder's settings that were corrupted.
Of course, dunno why it happened, but just glad I managed to sort it...