[plugins effects issue]

I have downloaded a bunch of plugins however when i try to drag the plugin dll's from the download zips into the effects folder they dont show up on the list of effects. I have googled it a bunch but i haven't found anything that helps. Please respond quick this is <No cursing.>ing annoying

[SP1 Problem for paint.net 4]

 fixed it!!! Thanks.

[SP1 Problem for paint.net 4]

 

 

I have windows 7 sp1 but its still not working. Please help me fix this because i only have 3.5 and i cant use it.