Yesterday my brother was trying to install cwm recovery and while booting it stuck and won't turn back again.

he can still go to download and recovery mode but the problem is that the computer is not recognizing the device when connected. (I guess it wasn't recognize it before this incident). the phone was already rooted.

Anyone may know what might be the problem|? Solution?

Thanks
The device wasn't being recognised even before the incident, was it just charging or ... ?
You might need a new USB charging board.
Adnan wroteThe device wasn't being recognised even before the incident, was it just charging or ... ?

It was just charging.
You lack the drivers? you can download the specific drivers or just install kies and kill the processes associated with it
That's a common problem with S2. Is it back to Gingerbread now? If so, upgrade to a different OS. I had that problem in Gingerbread and had to format the phone and upgrade to Jelly Bean for it to work out. Downloading KIES didn't fix the problem, nor did turning USB debugging on. But you can try these out.
m_zeid wroteYou lack the drivers? you can download the specific drivers or just install kies and kill the processes associated with it

no. all drivers installed.

all of a sudden the computer started to read the device.