Help using the BLUR Filter in PSE7

Question

I want to blur the background in some of my photos so that the main subject of the photo is sharp but all background items are blurred. When I try to do this in PSE7 it gives me a message 'could not complete your request as the layer is locked'. If I am able to get past this point how do I identify the subject from the background?

Answer 1

Hmmm. Blurring, as opposed to bandaging...
I don't know if this helps any, but - along a similar line of thought - I'd managed to load in a picture of a very wide, blue sky. Not much detail there, so what could possibly go wrong. After all, I'm just experimenting. -Then I tried out the bandage tool, sort of right in the middle of the sky, with blue all around it. (Some kind of a gradient had already been applied to it some time earlier; there is a zigzag mountain range somewhere much farther down.) The bandage tool attempts to look around its periphery, and fill into the middle, based on an 'average' of the periphery. I don't think it is actually averaging, in a mathematical sense, more than making a rough guess as to what the periphery represents, and then using that number, whatever it concocted together, as a sample, and then - having arrived at a sample - deposits a lot of that kind of stuff in the middle. (Remember, the bandage tool is used for filling in a hole, if my guess is correct.)
Is it really fixing the hole? Rather, it looks a lot more like some kind of interference pattern is being deposited on the blue sky, which can be a very pretty thing to look at, if that is what you are after. (At this point, the interference pattern can be cleaned up by switching to the blur tool; the bandage tool produces noticeable results much faster.)
But remember, the filling process depends a lot on the size of the circle you are using. It appears that you can adjust the size of the circle from a few pixels, up to a few hundred pixels. If you choose 400 pixels, that is probably too big to be useful.) Did you look above the drawing area, and find a place that indicates the size of the paintbrush can be changed? By golly, that little box also applies to the size of the blurring tool, and the bandage tool. All of those tools are different, but you can define each one of them by going up there and adjusting the pixel size. PSE 6 keeps track of the dimensions of the size of each of the tools. (For instance, I was using a circle that was about 175 pixels wide. -Maybe that's the radius, or maybe that's the diameter, I don't know. But for fixing up very small details, you should try using a circle that is about 7 or 8 pixels wide.)
If you switch back and forth from the bandage tool, which makes big changes, and the blur tool, which gets rid of minor smudges, you are probably going in the right direction.
Remember, you can zoom in and out by pressing Command + or Command -, and every time you change the order of magnitude you are dealing with, you should adjust the sizes of the tools you are using.
Like you, I am new to Photo Shop Elements 6. There is no way to learn without jumping in, and just seeing what you can do, and what happens when you switch from tool to tool.