I did everything you said, i even did some different things to get to the bin folder, but everything is in the bin folder EXCEPT for minecraft.jar and I dont know why. I did the part about showing hidden files but it doesn't work. And when i check the options again it still has the box checked for "Show hidden files folders and drives" but minecraft.jar just won't show! I've even tried reinstalling MC but it doesn't show! please help me :C
1. Open the start menu
2. Type in "show hidden files" into the search box
3. Click on the "show hidden files and folders" option, should show up under control panel
4. Under "Hidden files and folders", select the option that says; "show hidden files, folders, and drives"
5. Close the folder options window
6. Open the start menu
7. Open "Computer" or "My Computer"
8. Double-click on the hard drive
9. Double-click on the "Users" folder
10. Double-click on the folder with your username
11. Double-click on the "AppData" folder
12. Double-click on the "Roaming" folder
13. Double-click on the ".minecraft" folder
14. Double-click on the "bin" folder