can someone direct me to information on what to do about the following problem.

I download and unzup some kits and some are just in perfect use for me....sometimes I download kits and some items are represented by a windows icon and not the general photoshop or jpeg icon....I know I have to overwrite these icons to get them to work...but how do I know what ending to use....? I want to use all these papers and such but as they are unzipped in an un usable format I don't know what to do.

I am always scared to purchase kits becuase what if they come in the wrong format.? With that silly windows icon instead of the ones that I am familiar with.

Please Help or direct me to some help.

Thanks in advance

Roni