i try to open modpacks and it gives me an error

[mttprvst13]

Launcher Version: latest(when 1.5.2 origanal minecraft came out)

Operating System: windows 7

Java Version: 1.7

Antivirus Program: bitdefender antivirus plus 2012

Description of Problem:

Alright when i start up the program every things OK. And when i choose a modpack its alright. it downloads the files and everything. but when it starts, thats when the problem is...

it starts loading and downloading minecraft forge. and when i try to mod my origanal minecraft this happens it says:

Minecraft cannot in it's current configuration

Please consult the file C:Users****AppDataRoaming.technicbigdigForgeModloader-client-0.log for further information

Error Messages:

Minecraft cannot in it's current configuration

Please consult the file C:Users****AppDataRoaming.technicbigdigForgeModloader-client-0.log for further information

Error Log:

NONE- no recent one...