Photoshop 7 question
 

When I do not have my external USB harddrive connected this does not happen. It is only when it's connected and turned on. In photoshop the image you are working with will blink at random times. It's very annoying. I've set the ram to use less and I've set the scratch disks. That does not help. Any ideas? Your help is appreciated thanks!

My guess and this is just a guess is something on the external harddrive is booting up and sucking the ram for a short time. would more than likely be spyware or simular.

try reinstalling PS

I recomend to use some spyware removing tool on your computer, it used to happen to me and I solved it that way!