For those that are having problems opening the image in Photoshop:
Open Photoshop, and go to Edit > Preferences > Memory & Image Cache.
Set Physical Memory Usage "Used by Photoshop" to around 90%.
Now go to Edit > Preferences > Plug-ins & Scratch Disks.
Set up your scratch disks - the volume having the most free space available
should be listed first; the volume with the least free space available should be
listed last. Close Photoshop, and try opening the image again.
If Photoshop fails continues to give you the scratch disk error, your only
recourse is to either add RAM or a spare HD with some free space on it. Remember
to add any new scratch disk to Photoshop's preferences, or Photoshop will ignore
it.
Photoshop will take all the RAM & HD space you can throw at it, and then beg for
more. When I was doing commercial design work, our machines were equipped with
between 1-2 GB of RAM, and we still made extensive use of scratch disks.