i cant open my modpack folder under the launcher section of my tekkit folder

[jreerymonkey]

Launcher Version: 1.0.1.3

Operating System: windows 7

Java Version: version 7 update 6

Antivirus Program: ?

Description of Problem:

i opened the launcher, pressed options then pressed clear cache then it said "Failed to clear cache! Ensure Modpack files are open. if all else fails, close the launcher, restart it, and try again." i went in the folder like it said to to try and open it but i dont know any programs that will open it

Error Messages:

Error Log: