Go to Start > Run > (type) REGEDIT (hit enter)
Second Step: Navigate yourself to
>Under that open Vid_045e&Pid_04ec&MI_00
> Than open 6&2c1e16e4&0&0000
> Open Device Parameters.
Change following the Following values by Double Click on the File Names
Change Show In Shell from 0 to 1.
Change Portable Device Name Space Exclude From Shell from 1 to 0.
Change Enable Legacy Support from 0 to 1.
Now you have to Log off the computer or may be restart it to enable the changes (I guess not will not be necessary). Now plug in your Windows Phone 7. After plugging in you will notification of new hardware. Now you will be able to access all the files on your Windows Phone. Here you can easily perform simple operations like copy, paste, modify, rename or delete, etc.