Laptop Samsung RV409 cannot detect wireless network

My laptop cannot detect any wireless right now, though the others are connecting normally. But when I plugged the cable network in, my laptop can connect to wired network. Previously, it could be able to connect to wifi, but suddenly, the wifi is like hidden from it. I also tried to check the wireless drivers but I couldn't find any.
Please help me fix this problem.




Windows IP Configuration

Host Name . . . . . . . . . . . . : WIN7-UTI-PC
Primary Dns Suffix . . . . . . . :
Node Type . . . . . . . . . . . . : Mixed
IP Routing Enabled. . . . . . . . : No
WINS Proxy Enabled. . . . . . . . : No

PPP adapter Viettel:

Connection-specific DNS Suffix . :
Description . . . . . . . . . . . : Viettel
Physical Address. . . . . . . . . :
DHCP Enabled. . . . . . . . . . . : No
Autoconfiguration Enabled . . . . : Yes
IPv4 Address. . . . . . . . . . . : 27.64.246.80(Preferred)
Subnet Mask . . . . . . . . . . . : 255.255.255.255
Default Gateway . . . . . . . . . : 0.0.0.0
DNS Servers . . . . . . . . . . . : 203.113.131.2
203.113.188.1
Primary WINS Server . . . . . . . : 10.11.12.13
Secondary WINS Server . . . . . . : 10.11.12.14
NetBIOS over Tcpip. . . . . . . . : Disabled

Ethernet adapter Local Area Connection:

Media State . . . . . . . . . . . : Media disconnected
Connection-specific DNS Suffix . :
Description . . . . . . . . . . . : Realtek PCIe GBE Family Controller
Physical Address. . . . . . . . . : E8-11-32-2A-50-23
DHCP Enabled. . . . . . . . . . . : Yes
Autoconfiguration Enabled . . . . : Yes

Ethernet adapter Bluetooth Network Connection:

Media State . . . . . . . . . . . : Media disconnected
Connection-specific DNS Suffix . :
Description . . . . . . . . . . . : Bluetooth Device (Personal Area Network)
Physical Address. . . . . . . . . : 00-1B-B1-FA-AB-38
DHCP Enabled. . . . . . . . . . . : Yes
Autoconfiguration Enabled . . . . : Yes

Tunnel adapter isatap.{5293472D-EBA6-4C47-BC50-6FE6A35EC6F2}:

Media State . . . . . . . . . . . : Media disconnected
Connection-specific DNS Suffix . :
Description . . . . . . . . . . . : Microsoft ISATAP Adapter
Physical Address. . . . . . . . . : 00-00-00-00-00-00-00-E0
DHCP Enabled. . . . . . . . . . . : No
Autoconfiguration Enabled . . . . : Yes

Tunnel adapter Teredo Tunneling Pseudo-Interface:

Connection-specific DNS Suffix . :
Description . . . . . . . . . . . : Teredo Tunneling Pseudo-Interface
Physical Address. . . . . . . . . : 00-00-00-00-00-00-00-E0
DHCP Enabled. . . . . . . . . . . : No
Autoconfiguration Enabled . . . . : Yes
IPv6 Address. . . . . . . . . . . : 2001:0:4137:9e76:202c:1265:e4bf:9af(Preferred)
Link-local IPv6 Address . . . . . : fe80::202c:1265:e4bf:9af%19(Preferred)
Default Gateway . . . . . . . . . :
DHCPv6 IAID . . . . . . . . . . . : 335544320
DHCPv6 Client DUID. . . . . . . . : 00-01-00-01-15-70-AE-AD-E8-11-32-2A-50-23
NetBIOS over Tcpip. . . . . . . . : Disabled

Tunnel adapter isatap.{FD6E71BD-DEB7-41F9-A212-79AD82C4502C}:

Media State . . . . . . . . . . . : Media disconnected
Connection-specific DNS Suffix . :
Description . . . . . . . . . . . : Microsoft ISATAP Adapter #3
Physical Address. . . . . . . . . : 00-00-00-00-00-00-00-E0
DHCP Enabled. . . . . . . . . . . : No
Autoconfiguration Enabled . . . . : Yes

Tunnel adapter isatap.{D46AC1EE-CE29-46BB-A69C-EBA0D84A7893}:

Media State . . . . . . . . . . . : Media disconnected
Connection-specific DNS Suffix . :
Description . . . . . . . . . . . : Microsoft ISATAP Adapter #4
Physical Address. . . . . . . . . : 00-00-00-00-00-00-00-E0
DHCP Enabled. . . . . . . . . . . : No
Autoconfiguration Enabled . . . . : Yes

Tunnel adapter 6TO4 Adapter:

Connection-specific DNS Suffix . :
Description . . . . . . . . . . . : Microsoft 6to4 Adapter
Physical Address. . . . . . . . . : 00-00-00-00-00-00-00-E0
DHCP Enabled. . . . . . . . . . . : No
Autoconfiguration Enabled . . . . : Yes
IPv6 Address. . . . . . . . . . . : 2002:1b40:f650::1b40:f650(Preferred)
Default Gateway . . . . . . . . . : 2002:c058:6301::1
DNS Servers . . . . . . . . . . . : 203.113.131.2
203.113.188.1
NetBIOS over Tcpip. . . . . . . . : Disabled

No it doesn't. In fact, I hadn't known about that Fn+F9 thing at first, but then, my friend had told me about that and I've tried it already. Unfortunately, it still didn't work.
That's why I have to ask here.
And FYI, it's so strange, but the Wifi switch is always on, no matter how many times I press Fn+F9 (and the wifi is still hidden).
Could you tell me more about solution to fix this problem, please?

Sorry you guys for replying late.
The third light below the touchpad is always on, whether I press Fn+F9 or not. And when I do that, there is nothing happen on the screen as well.

For the device manager, I understand that there has been no wireless driver there. The problem is that, I have uninstalled and re-installed all the wireless driver so many times (Atheros - WLAN_Atheros_32bit_8.0.0.366 and Broadcom - WLAN_Broadcom_32bit_5.60.350.21), but nothing changed.

I don't know what is going on with my laptop. Now, the wireless driver is back on the device manager, but I cannot understand why? Because, after two days of installing the driver without any success, now it suddenly appears and my wifi is back.

Some says that it is because my hardware is unstable, is that true?

Anyway, thank you guys for all your concern. My wifi is back now, but does anyone know about my problem? I'm really worried, because this thing happened three times in the past 2 months, and I couldn't figure out what the cause is. Do I need to fix the hardware?

Fn+F9 still changes nothing.