lsb_release -rd
Description:    Ubuntu 14.04.1 LTS
Release:        14.04

uname -a
Linux Work 3.13.0-36-generic #63-Ubuntu SMP Wed Sep 3 21:30:07 UTC 2014 x86_64 x86_64 x86_64 GNU/Linux

apt-cache policy nvidia-331 nvidia-prime
nvidia-331:
  Installato: 331.38-0ubuntu7.1
  Candidato:  331.38-0ubuntu7.1
  Tabella versione:
 *** 331.38-0ubuntu7.1 0
        500 http://it.archive.ubuntu.com/ubuntu/ trusty-updates/restricted amd64 Packages
        100 /var/lib/dpkg/status
     331.38-0ubuntu7 0
        500 http://it.archive.ubuntu.com/ubuntu/ trusty/restricted amd64 Packages
nvidia-prime:
  Installato: 0.6.2
  Candidato:  0.6.2
  Tabella versione:
 *** 0.6.2 0
        500 http://it.archive.ubuntu.com/ubuntu/ trusty/main amd64 Packages
        100 /var/lib/dpkg/status

cat /var/log/prime-supported.log
Requires offloading

lspci -v
00:00.0 Host bridge: Intel Corporation Xeon E3-1200 v3/4th Gen Core Processor DRAM Controller (rev 06)
        Subsystem: Dell Device 05cc
        Flags: bus master, fast devsel, latency 0
        Capabilities: <access denied>

00:01.0 PCI bridge: Intel Corporation Xeon E3-1200 v3/4th Gen Core Processor PCI Express x16 Controller (rev 06) (prog-if 00 [Normal decode])
        Flags: bus master, fast devsel, latency 0
        Bus: primary=00, secondary=01, subordinate=01, sec-latency=0
        I/O behind bridge: 0000e000-0000efff
        Memory behind bridge: f3000000-f40fffff
        Prefetchable memory behind bridge: 00000000d0000000-00000000e1ffffff
        Capabilities: <access denied>
        Kernel driver in use: pcieport

00:02.0 VGA compatible controller: Intel Corporation 4th Gen Core Processor Integrated Graphics Controller (rev 06) (prog-if 00 [VGA controller])
        Subsystem: Dell Device 05cc
        Flags: bus master, fast devsel, latency 0, IRQ 255
        Memory at f5400000 (64-bit, non-prefetchable) [size=4M]
        Memory at c0000000 (64-bit, prefetchable) [size=256M]
        I/O ports at f000 [size=64]
        Expansion ROM at <unassigned> [disabled]
        Capabilities: <access denied>

00:03.0 Audio device: Intel Corporation Xeon E3-1200 v3/4th Gen Core Processor HD Audio Controller (rev 06)
        Subsystem: Dell Device 05cc
        Flags: bus master, fast devsel, latency 0, IRQ 52
        Memory at f7734000 (64-bit, non-prefetchable) [size=16K]
        Capabilities: <access denied>
        Kernel driver in use: snd_hda_intel

00:14.0 USB controller: Intel Corporation 8 Series/C220 Series Chipset Family USB xHCI (rev 04) (prog-if 30 [XHCI])
        Subsystem: Dell Device 05cc
        Flags: bus master, medium devsel, latency 0, IRQ 47
        Memory at f7720000 (64-bit, non-prefetchable) [size=64K]
        Capabilities: <access denied>
        Kernel driver in use: xhci_hcd

00:16.0 Communication controller: Intel Corporation 8 Series/C220 Series Chipset Family MEI Controller #1 (rev 04)
        Subsystem: Dell Device 05cc
        Flags: bus master, fast devsel, latency 0, IRQ 49
        Memory at f7740000 (64-bit, non-prefetchable) [size=16]
        Capabilities: <access denied>
        Kernel driver in use: mei_me

00:19.0 Ethernet controller: Intel Corporation Ethernet Connection I217-LM (rev 04)
        Subsystem: Dell Device 05cc
        Flags: bus master, fast devsel, latency 0, IRQ 50
        Memory at f7700000 (32-bit, non-prefetchable) [size=128K]
        Memory at f773d000 (32-bit, non-prefetchable) [size=4K]
        I/O ports at f080 [disabled] [size=32]
        Capabilities: <access denied>
        Kernel driver in use: e1000e

00:1a.0 USB controller: Intel Corporation 8 Series/C220 Series Chipset Family USB EHCI #2 (rev 04) (prog-if 20 [EHCI])
        Subsystem: Dell Device 05cc
        Flags: bus master, medium devsel, latency 0, IRQ 16
        Memory at f773c000 (32-bit, non-prefetchable) [size=1K]
        Capabilities: <access denied>
        Kernel driver in use: ehci-pci

00:1b.0 Audio device: Intel Corporation 8 Series/C220 Series Chipset High Definition Audio Controller (rev 04)
        Subsystem: Dell Device 05cc
        Flags: bus master, fast devsel, latency 0, IRQ 51
        Memory at f7730000 (64-bit, non-prefetchable) [size=16K]
        Capabilities: <access denied>
        Kernel driver in use: snd_hda_intel

00:1c.0 PCI bridge: Intel Corporation 8 Series/C220 Series Chipset Family PCI Express Root Port #1 (rev d4) (prog-if 00 [Normal decode])
        Flags: bus master, fast devsel, latency 0
        Bus: primary=00, secondary=02, subordinate=02, sec-latency=0
        I/O behind bridge: 00002000-00002fff
        Memory behind bridge: bf200000-bf3fffff
        Prefetchable memory behind bridge: 00000000bf400000-00000000bf5fffff
        Capabilities: <access denied>
        Kernel driver in use: pcieport

00:1c.2 PCI bridge: Intel Corporation 8 Series/C220 Series Chipset Family PCI Express Root Port #3 (rev d4) (prog-if 00 [Normal decode])
        Flags: bus master, fast devsel, latency 0
        Bus: primary=00, secondary=03, subordinate=07, sec-latency=0
        I/O behind bridge: 0000d000-0000dfff
        Memory behind bridge: f4800000-f53fffff
        Prefetchable memory behind bridge: 00000000e2800000-00000000e2ffffff
        Capabilities: <access denied>
        Kernel driver in use: pcieport

00:1c.3 PCI bridge: Intel Corporation 8 Series/C220 Series Chipset Family PCI Express Root Port #4 (rev d4) (prog-if 00 [Normal decode])
        Flags: bus master, fast devsel, latency 0
        Bus: primary=00, secondary=08, subordinate=0b, sec-latency=0
        I/O behind bridge: 0000c000-0000cfff
        Memory behind bridge: f6c00000-f75fffff
        Prefetchable memory behind bridge: 00000000e4400000-00000000e4dfffff
        Capabilities: <access denied>
        Kernel driver in use: pcieport

00:1c.4 PCI bridge: Intel Corporation 8 Series/C220 Series Chipset Family PCI Express Root Port #5 (rev d4) (prog-if 00 [Normal decode])
        Flags: bus master, fast devsel, latency 0
        Bus: primary=00, secondary=0c, subordinate=0c, sec-latency=0
        I/O behind bridge: 0000b000-0000bfff
        Memory behind bridge: f6200000-f6bfffff
        Prefetchable memory behind bridge: 00000000e3a00000-00000000e43fffff
        Capabilities: <access denied>
        Kernel driver in use: pcieport

00:1c.6 PCI bridge: Intel Corporation 8 Series/C220 Series Chipset Family PCI Express Root Port #7 (rev d4) (prog-if 00 [Normal decode])
        Flags: bus master, fast devsel, latency 0
        Bus: primary=00, secondary=0d, subordinate=14, sec-latency=0
        I/O behind bridge: 00009000-0000afff
        Memory behind bridge: f5800000-f61fffff
        Prefetchable memory behind bridge: 00000000e3000000-00000000e39fffff
        Capabilities: <access denied>
        Kernel driver in use: pcieport

00:1c.7 PCI bridge: Intel Corporation 8 Series/C220 Series Chipset Family PCI Express Root Port #8 (rev d4) (prog-if 00 [Normal decode])
        Flags: bus master, fast devsel, latency 0
        Bus: primary=00, secondary=15, subordinate=15, sec-latency=0
        Memory behind bridge: f7600000-f76fffff
        Capabilities: <access denied>
        Kernel driver in use: pcieport

00:1d.0 USB controller: Intel Corporation 8 Series/C220 Series Chipset Family USB EHCI #1 (rev 04) (prog-if 20 [EHCI])
        Subsystem: Dell Device 05cc
        Flags: bus master, medium devsel, latency 0, IRQ 21
        Memory at f773b000 (32-bit, non-prefetchable) [size=1K]
        Capabilities: <access denied>
        Kernel driver in use: ehci-pci

00:1f.0 ISA bridge: Intel Corporation QM87 Express LPC Controller (rev 04)
        Subsystem: Dell Device 05cc
        Flags: bus master, medium devsel, latency 0
        Capabilities: <access denied>
        Kernel driver in use: lpc_ich

00:1f.2 RAID bus controller: Intel Corporation 82801 Mobile SATA Controller [RAID mode] (rev 04)
        Subsystem: Dell Device 05cc
        Flags: bus master, 66MHz, medium devsel, latency 0, IRQ 48
        I/O ports at f0d0 [size=8]
        I/O ports at f0c0 [size=4]
        I/O ports at f0b0 [size=8]
        I/O ports at f0a0 [size=4]
        I/O ports at f060 [size=32]
        Memory at f773a000 (32-bit, non-prefetchable) [size=2K]
        Capabilities: <access denied>
        Kernel driver in use: ahci

00:1f.3 SMBus: Intel Corporation 8 Series/C220 Series Chipset Family SMBus Controller (rev 04)
        Subsystem: Dell Device 05cc
        Flags: medium devsel, IRQ 255
        Memory at f7739000 (64-bit, non-prefetchable) [size=256]
        I/O ports at f040 [size=32]

01:00.0 VGA compatible controller: NVIDIA Corporation GK107GLM [ ] (rev a1) (prog-if 00 [VGA controller])
        Subsystem: Dell Device 15cc
        Flags: bus master, fast devsel, latency 0, IRQ 16
        Memory at f3000000 (32-bit, non-prefetchable) [size=16M]
        Memory at d0000000 (64-bit, prefetchable) [size=256M]
        Memory at e0000000 (64-bit, prefetchable) [size=32M]
        I/O ports at e000 [size=128]
        Expansion ROM at f4000000 [disabled] [size=512K]
        Capabilities: <access denied>
        Kernel driver in use: nvidia

03:00.0 PCI bridge: Wilocity Ltd. Wil6200 PCI Express Root Port (rev 03) (prog-if 00 [Normal decode])
        Flags: bus master, fast devsel, latency 0
        Memory at f5200000 (32-bit, non-prefetchable) [size=2M]
        Bus: primary=03, secondary=04, subordinate=07, sec-latency=0
        I/O behind bridge: 0000d000-0000dfff
        Memory behind bridge: f4800000-f50fffff
        Prefetchable memory behind bridge: 00000000e2800000-00000000e2ffffff
        Capabilities: <access denied>
        Kernel driver in use: pcieport

04:00.0 PCI bridge: Wilocity Ltd. Wil6200 PCI Express Port (rev 03) (prog-if 00 [Normal decode])
        Flags: bus master, fast devsel, latency 0
        Bus: primary=04, secondary=05, subordinate=05, sec-latency=0
        Memory behind bridge: f5000000-f50fffff
        Capabilities: <access denied>
        Kernel driver in use: pcieport

04:02.0 PCI bridge: Wilocity Ltd. Wil6200 Wireless PCI Express Port (rev 13) (prog-if 00 [Normal decode])
        Flags: bus master, fast devsel, latency 0
        Memory at e2800000 (32-bit, prefetchable) [size=8M]
        I/O ports at d100 [size=256]
        Bus: primary=00, secondary=06, subordinate=06, sec-latency=0
        Capabilities: <access denied>
        Kernel driver in use: pcieport

04:03.0 PCI bridge: Wilocity Ltd. Wil6200 Wireless PCI Express Port (rev 13) (prog-if 00 [Normal decode])
        Flags: bus master, fast devsel, latency 0
        Memory at f4800000 (32-bit, non-prefetchable) [size=8M]
        I/O ports at d000 [size=256]
        Bus: primary=00, secondary=07, subordinate=07, sec-latency=0
        Capabilities: <access denied>
        Kernel driver in use: pcieport

05:00.0 Network controller: Qualcomm Atheros AR9462 Wireless Network Adapter (rev 01)
        Subsystem: Dell Device 020b
        Flags: bus master, fast devsel, latency 0, IRQ 18
        Memory at f5000000 (64-bit, non-prefetchable) [size=512K]
        Expansion ROM at f5080000 [disabled] [size=64K]
        Capabilities: <access denied>
        Kernel driver in use: ath9k

15:00.0 SD Host controller: O2 Micro, Inc. SD/MMC Card Reader Controller (rev 01) (prog-if 01)
        Subsystem: Dell Device 05cc
        Flags: bus master, fast devsel, latency 0, IRQ 19
        Memory at f7601000 (32-bit, non-prefetchable) [size=4K]
        Memory at f7600000 (32-bit, non-prefetchable) [size=2K]
        Capabilities: <access denied>
        Kernel driver in use: sdhci-pci

[steps to reproduce]

Boot and wait for login screen. After entering password, the desktop environment (lightdm) crashes and a popup is shown: "ksmserver could not start: check your installation".
The only way left to interact with the system is via CLI after typing ctrl-FN