how  can i use the downloaded blocks when they are in read only format  thanks Ron

I've never encountered a block that I downloaded that was in read-only format.  If I did I would remove this attribute via Windows Explorer.

It shouldn't matter if they are "read only" or not. You will still be able to insert them into your drawings regardless. Unless you're talking about editing them before using them in your drawings. If that's the case, then just remove the "read only" flag in the drawing properties in Explorer, as John suggested.

When you download it and open a drawing/block if you did not create it first opening is read only when you save it then the read only drops out.  It is letting you know that until saved on your computer/network no changes will be saved...

Only if you do a "Save As". You cannot "Save" a file that is Read Only.