Having problems opening some files with notepad. Or anything?

I have been hosting a Minecraft server for me and a few close friends lately, and randomly I started getting this problem.

When I go to open the "server.properties" file i get an error message saying this

"This file does not have a program associated with it for performing this action. Please install a program or, if one is already installed, create an association in the Default Programs control panel."

I've tried to go to the Default Programs and associate a file with the.properties folder but couldn't find it. I have also tried right clicking in the "server.properties" folder and going into its properties and changing the Open With program which is already set to "unknown application" to notepad but it does not respond and nothing has been changed.

I'm at a loss of what to do next, anybody please help.

Guest

Do these files have ANY file extension, and if so what is the extension? Have you tried right clicking the files and selecting "open with"? Be VERY careful with setting default programs to open files, one mistake with that and tyou can end up with a machine that will not open ANY program. Ther is NO fx for that as Microsoft seem to think nobody csn make that mistake.

Fred