i tried the above things but still not working
i found this thing which may be the issue:-

System Profiler:-
Audio (Built In):-

Intel High Definition Audio:

Device ID: 0x103C30E5
Audio ID: 12
Available Devices:

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HP TX2000
Microprocessor: AMD Turion 64 X2 Mobile Technology TL-60
Memory: 2048 MB
Video Graphics: NVIDIA GeForce Go 6150
Network Card: Ethernet 10/100BT integrated network interfaceWireless
Connectivity: 802.11b/g WLAN - Bluetooth
Sound: Altec Lansing speakers - 3D Sound Blaster Pro
Pointing Device: Touch Pad with On/Off button and dedicated vertical Scroll Up/Down pad, volume control, mute buttons, 2 Quick Launch Button