Windows Explorer (file manager) freezes repeatedly

Hi,

I usually take good care of my system and more or less know what goes on, in
and out. If not, I can usually detect the source of problems by myself. This
time however, I am at a loss.

I use the Explorer file manager a lot, for starting and moving and handling
files on my computer between my various HDs. I have the folder pane open to
the left and the files/folders on display to the right. I do quite a lot of
file management (geek=me) and on a regular day Explorer is almost always open
and heavily used.

Since a week or so, Explorer is acting up on me though. Without any increase
in the number of files on my system it hangs/freezes very easily when I click
folders to see its contents. I used to be able to blaze through my directory
trees to the folder I wanted and visualize the contents, but now I almost
always get stuck on the way. When this happens the contents of a folder
refuses to visualize and sometimes it appears after a minute or so but most
of the time it never does and I have to shut down Explorer from the Task
Manager in order to be able to launch a new and working Explorer window.
Which may well freeze after ten seconds or minutes.

I have the impression that if I click slowly and leave a few seconds in
between clicks when going into a directory tree or moving between disks, it
freezes less often, but it will still freeze annoyingly often.

I have also noted that lately, files that I want to delete are often "being
busy, and used by the system". Even upon reboot, they remain locked and can't
be deleted. All kinds of files. Even 50Kb text files, so it can't be that
they are being defragmented and thus can't be deleted which I thought at
first.

After a couple of forced shut downs of frozen Explorer windows or maybe a
reboot or two, those files can always be deleted.

All disks are extremely well defragmented by Diskeeper 12 which is running
resident and is doing its work all the time. I am well protected from malware
and Kaspersky scans have revealed no intrusions.

I am fearing that all my harddrives (3 (with a total of 6 partitions)) are
dying simultaneously or something.

Or maybe my (admittedly weighty) Windows installation is beginning to be too
heavy and simply needs reinstalling?

Does anyone recognize these symptoms?
Is there a log where I can see why Explorer is acting up on me?

Thanks a lot!

/peter