I have tried most of the advice on askubuntu and other sites, usb_storage enable to fdisk -l. But I am unable to find steps to get it working again.

lsusb results

Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub 
Bus 002 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub 
Bus 003 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub 
Bus 004 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub 
Bus 005 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub 
Bus 004 Device 002: ID 413c:3012 Dell Computer Corp. Optical Wheel Mouse 
Bus 005 Device 002: ID 413c:2105 Dell Computer Corp. Model L100 Keyboard 
Bus 001 Device 005: ID 8564:1000

dmseg | tail reports

[   69.567948] usb 1-4: USB disconnect, device number 4
[   74.084041] usb 1-6: new high-speed USB device number 5 using ehci_hcd
[   74.240484] Initializing USB Mass Storage driver...
[   74.256033] scsi5 : usb-storage 1-6:1.0
[   74.256145] usbcore: registered new interface driver usb-storage
[   74.256147] USB Mass Storage support registered.
[   74.257290] usbcore: deregistering interface driver usb-storage

fdisk -l reports

Device Boot      Start         End      Blocks   Id  System
/dev/sda1   *        2048   972656639   486327296   83  Linux
/dev/sda2       972658686   976771071     2056193    5  Extended
/dev/sda5       972658688   976771071     2056192   82  Linux swap / Solaris

I think I need steps to install and get usb_storage module working.

Edit : I tried sudo modprobe -v usb-storage reports

sudo modprobe -v usb-storage
insmod /lib/modules/3.2.0-48-generic-pae/kernel/drivers/usb/storage/usb-storage.ko 

Still no usb driver mounted. Nor does a device show up in /dev. Any step by step process to debug and fix this will be really helpful. Thanks.