List of wifi network not showing on ubuntu 17.10

I have a dell latitude d620 on which i run both window 7 and ubuntu 17.10. but i discovered that whenever i log on ubuntu, it doesn't always find any network. it always search forever, something which is different when i log on to windows. i have gone through many thread, but their answers seems not helping. i will post the list of codes that i have run below and their result.

sudo lshw -C network
*-network description: Wireless interface product: PRO/Wireless 3945ABG [Golan] Network Connection vendor: Intel Corporation physical id: 0 bus info: pci@0000:0c:00.0 logical name: wlp12s0 version: 02 serial: 00:19:d2:49:fc:6f width: 32 bits clock: 33MHz capabilities: pm msi pciexpress bus_master cap_list ethernet physical wireless configuration: broadcast=yes driver=iwl3945 driverversion=4.13.0-38-generic firmware=15.32.2.9 latency=0 link=no multicast=yes wireless=IEEE 802.11 resources: irq:24 memory:efdff000-efdfffff *-network DISABLED description: Ethernet interface product: NetXtreme BCM5752 Gigabit Ethernet PCI Express vendor: Broadcom Limited physical id: 0 bus info: pci@0000:09:00.0 logical name: enp9s0 version: 02 serial: 00:18:8b:a6:60:41 capacity: 1Gbit/s width: 64 bits clock: 33MHz capabilities: pm vpd msi pciexpress bus_master cap_list ethernet physical tp 10bt 10bt-fd 100bt 100bt-fd 1000bt 1000bt-fd autonegotiation configuration: autonegotiation=on broadcast=yes driver=tg3 driverversion=3.137 firmware=5752-v3.19 latency=0 link=no multicast=yes port=twisted pair resources: irq:18 memory:efcf0000-efcfffff

I tried

iwlist wlan0 scan

But it said

wlan0 Interface doesn't support scanning.

I tried:

iwconfig

result

wlp12s0 IEEE 802.11 ESSID:off/any Mode:Managed Access Point: Not-Associated Tx-Power=15 dBm Retry short limit:7 RTS thr:off Fragment thr:off Power Management:off
lo no wireless extensions.
enp9s0 no wireless extensions.

i tried this

lspci | grep -i -E wireless\|ethernet 

and got this

 09:00.0 Ethernet controller: Broadcom Limited NetXtreme BCM5752 Gigabit Ethernet PCI Express (rev 02).
0c:00.0 Network controller: Intel Corporation PRO/Wireless 3945ABG [Golan] Network Connection (rev 02)

This also:

sudo iwlist wlp12s0 s 

always see some network, but will not display it in the GUI

wlp12s0 Scan completed : Cell 01 - Address: A4:BA:76:74:97:EA Channel:6 Frequency:2.437 GHz (Channel 6) Quality=64/70 Signal level=-46 dBm Encryption key:off ESSID:"Xender_APd5dc" Bit Rates:1 Mb/s; 2 Mb/s; 5.5 Mb/s; 11 Mb/s; 18 Mb/s 24 Mb/s; 36 Mb/s; 54 Mb/s Bit Rates:6 Mb/s; 9 Mb/s; 12 Mb/s; 48 Mb/s Mode:Master Extra:tsf=0000000001b34f0d Extra: Last beacon: 28ms ago IE: Unknown: 000D58656E6465725F415064356463 IE: Unknown: 010882848B962430486C IE: Unknown: 030106 IE: Unknown: 0706555320010B1E IE: Unknown: 200100 IE: Unknown: 23021300 IE: Unknown: 2A0100 IE: Unknown: 32040C121860 IE: Unknown: 2D1A200017FF00000000000000000000000000000000000000000000 IE: Unknown: 3D1606080000000000000000000000000000000000000000 IE: Unknown: 7F0104 IE: Unknown: DD090010180200000C0000 IE: Unknown: DD180050F2020101800003A4000027A4000042435E0062322F00

pls i need help, i've been on this for weeks.

cat /etc/NetworkManager/NetworkManager.conf

the result is below:

[main]
plugins=ifupdown,keyfile
[ifupdown]
managed=false
[device]
wifi.scan-rand-mac-address=no

for the second command

cat /etc/network/interfaces 

The result is as follow:

/etc/network/interfaces -- configuration file for
ifup(8), ifdown(8) Generated by debian-installer. The loopback interface auto lo iface lo inet loopback 

I also noticed that my computer do connect with the network that i use to set it up during installation whenever the network is available. Its a wireless network from my phone. But it won't even show the name of that network nor other networks. But my phone always tell me when the laptop connect with its hotspot. So i can't use any other WiFi network except one with that very name and password.pls i need help::,

1 Answer

Network manager was the problem, that thing made me suffer for 6 months. I solved this by running the following codes:

sudo apt-get install wicd
sudo service network-manager stop
sudo service wicd start