I have been watching someone try to solve a problem with a laptop
failing to boot. It's in The Avast Forum.
http://forum.avast.com/index.php?board=4.0
They have been using third party tools for several days with no success.
From what I have read, parallel installation is just installing the
same operating system on the same hard drive in another partition.
It looks to me like this would be a clean install, and not be affected
by the damaged installation. If important files from the damaged
installation could be moved to the new partition, then the original
installation could be removed.
If it turns out there is no problem with the hard drive, and they still
can't solve the problem, I was going to suggest the parallel installation.
I was just wondering if anyone has done this, and if it works?
I've done it, but not for a long time. If you install a new copy of
windows on a different partition it will usually be able to access files
on another. Do you have a suitable (empty?) partition? If not, there
are tools which can resize an existing partition and create a new one in
the released space - I use Acronis Disk Director or Paragon Hard disk
manager for this.
However, you may not need to do this. My first step would be to boot
the machine from a "live" CD, and access the files that way. You may
also be able to repair the broken installation. My first action is to
check the disk at a low level using Spinrite (bootable, mid-price), then
use another disk to provide a means of running chkdsk; I use UBCD4Win
for this but the Windows 7 DVD also has this available (command prompt
mode). Then, if the disk is crumbling, it becomes a matter of
recovering the data. If not, then you can find articles on the web
about how to fix a Windows 7 installation that won't boot.
I guess if you know the disk is physically healthy and you already have
a blank partition (or empty space in which to create one) then a
parallel installation is one way to get your files back, but using a
bootable CD is much easier and quicker, and doesn't risk pushing the
disk into failure quite so much.