While I have not read ALL of the responses in this 'thread' I just wish to add my 'bit', even at this late date.
I acquired a 'new' computer, with Windows 7 Ultimate, in late 2009. While I had NOT transferred to it most of my applications by April 2010 (due to the pressure of other activities) at about that time I started to receive an increasing number of 'Not Responding' messages. I left this in abeyance while going on a holiday in mid year but, when I returned, the problem was as bad (or worse) than ever!
Eventually, I reformatted the hard drive, re-installed Windows 7 and then also installed Windows XP as a dual boot on the same drive. The 'Not Responding' problem was, if anything, WORSE with the XP installation than with the Windows 7 installation.
Obvious conclusion: - there is something wrong with the hard drive.
Actually, I had two 1tB hard drives, so I copied the operating systems file images from one to the other. The problem was just as bad on the second hard drive, if not worse.
I did a little checking, using 'HD Tune' on "Ultimate Boot CD for Windows" (
Ultimate Boot CD - Overview) and found that while both hard drives would gradually decay in their transfer rate there were MANY dramatic NIL responses for MANY seconds (minutes?) on both of them!
(I can recommend the Ultimate Boot CD software. It is free but you need a copy of Windows XP, from wherever you can get it if you do not own a copy yourself. to create a CD. Also, if you include ALL of the options, you may exceed the capacity of a CD - so you may need to use a DVD.)
Now, both of these defective hard drives were 1tB Western Digital hard drives.
In October, I copied the operating systems file images to a new 1tB hard drive (Seagate) and, to date - no further problems. (The second hard drive has (of course) also been replaced - with a Seagate.
[Does anyone want a pair of (cheap) 1tB Western Digital hard drives?]