Scratch Disk...

I know that problems with the scratch disk are common,
But I can't seem to fix mine!

When I attempt to load photoshop,
A pop up box appears saying that the selected scratch disks are almost full,
and there are 4 drop down boxes: First, Second, Third, Fourth.
With the "First", with either Startup or C drive selected, photoshop won't load.
This pop up box has never appeared before.

So, when I press ok on this box, photoshop continues to load for a few seconds then it states that it cannot continue loading because there was an error that it couldn't recover from! :(

There are no PST temporary files located on my computer,
And it isn't the "working with large image" problem because I don't even GET to open photoshop in the first place!!

I'm sooo confused, any help is appreciated :(
Thanks.

Reset prefererences when trying to start PS, check your hard drives. Once you open PS and you will make sure only 70% is use for PS, leave something for rest of system.