xperia s usb error!

[must]

hi first, i'm sorry about my English.
my phone is xperia s and i have problom with usb connection.
honestly, i rooted my phone, and i tried to connect my phone and pc by msc mode.
but i failed, and there's problem with my phone. so i want to know how to fix it.
when i connect PC and my phone, my phone can't recogized and it just charging.
setting my phone setting-xperia-usb connection-install pc companion, and connect with pc, pop up the messege in my phone that install pc companion or not.
i click install, in that case, pc recognize my phone.
ah, also i choose not, my phone is recognize just f drive.
and, computer-device manager, click the disk drive, there is 'sony mass storage usb device'.
please help me!

[Rickard]

If you haven't unlocked the phones bootloader, try repairing the phone software using PC Companion and see if it helps. Start PC Companion without connecting the phone and go to Support zone -> Software update -> repair and then follow the instructions from the software.

If you have unlocked the bootloader, try reinstalling the firmware using Emma: http://developer.sonymobile.com/downloads/tool/flash-tool-for-xperia-devices/