Can't delete unwanted .dll files

I constantly clean out my files by going to my computer/local disk drive/program files I only delete files that I know are useless. If i don't know what it is I wont touch it. Well I've found two .dll files called "web specials" and "my way search bar" . I know they came from internet downloads such as the p2p search sites b/c that was the last program i downloaded from the internet and then those files appeared. I've tried to change the .dll to .old (b/c that was suggested), but that didn't work. I've already tried the Ad Aware program and that didn't work . In another forum they recommended I use "who locked me out" which I did and it helped me to remove "my way search bar," but I still Can't delete "web specials." Every time I try to delete the .dll file it says:  

                                  Can not delete webspec.dll: Access denied.

                                  Make sure the disk is not full or write-protected

                                  and that the file is not currently in use.

When i try to uninstall the program from within the file it says to use the add/remove program, so i went there and it is not listed as being installed. At this point i don't know what to do and I'm not really computer literate, so i need someone who can help me delete these files and explain it in elementary terms. Please help! Thanks