Hi, I also had the problem where my kubuntu 12.04 install was completely hardware freezing - i.e absolutely no response from any input device and in particular CTRL+ALT+SysRq REISUB was not responding at all either. I found the problem was happening close to when I was switching the external monitor on & off (I switch it via a KVM switch). Note that I use x11vnc to remotely connect to the same desktop, and I think that may have helped trigger the fault. I updated ALL installed software, but to no avail, it was happening 3 or 4 times a day ... *** THE FOLLOWING FIX WORKED FOR ME -been ROCK SOLID for a week now *** I installed the following kernel upgrade described here: http://askubuntu.com/questions/142192/can-i-install-linux-kernel-3-4-in-ubuntu-and-kubuntu-12-04 So I downloaded from: http://kernel.ubuntu.com/~kernel-ppa/mainline/v3.4-precise/ And did: sudo dpkg -i linux-headers-3.4.0-030400_3.4.0-030400.201205210521_all.deb sudo dpkg -i linux-headers-3.4.0-030400-generic_3.4.0-030400.201205210521_i386.deb sudo dpkg -i linux-image-3.4.0-030400-generic_3.4.0-030400.201205210521_i386.deb Rebooted, and the problem completely disappeared (so far anyway !) My machine specs: uname -r 3.4.0-030400-generic MOBO: ASUS P8Z77-V-LX I am using the onboard video, with nothing but the default kubuntu video installation. lshw output follows: bridge2 description: Computer width: 64 bits capabilities: vsyscall32 *-core description: Motherboard physical id: 0 *-memory description: System memory physical id: 0 size: 31GiB *-cpu product: Intel(R) Core(TM) i7-3770 CPU @ 3.40GHz vendor: Intel Corp. physical id: 1 bus info: cpu@0 size: 1600MHz capacity: 1600MHz width: 64 bits capabilities: fpu fpu_exception wp vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat pse36 clflush dts acpi mmx fxsr sse sse2 ss ht tm pbe syscall nx rdtscp x86-64 constant_tsc arch_perfmon pebs bts rep_good nopl xtopology nonstop_tsc aperfmperf pni pclmulqdq dtes64 monitor ds_cpl vmx smx est tm2 ssse3 cx16 xtpr pdcm pcid sse4_1 sse4_2 x2apic popcnt tsc_deadline_timer aes xsave avx f16c rdrand lahf_lm ida arat epb xsaveopt pln pts tpr_shadow vnmi flexpriority ept vpid fsgsbase smep erms cpufreq *-pci description: Host bridge product: Ivy Bridge DRAM Controller vendor: Intel Corporation physical id: 100 bus info: pci@0000:00:00.0 version: 09 width: 32 bits clock: 33MHz configuration: driver=agpgart-intel resources: irq:0 *-pci:0 description: PCI bridge product: Ivy Bridge PCI Express Root Port vendor: Intel Corporation physical id: 1 bus info: pci@0000:00:01.0 version: 09 width: 32 bits clock: 33MHz capabilities: pci normal_decode bus_master cap_list configuration: driver=pcieport resources: irq:42 *-display description: VGA compatible controller product: Ivy Bridge Graphics Controller vendor: Intel Corporation physical id: 2 bus info: pci@0000:00:02.0 version: 09 width: 64 bits clock: 33MHz capabilities: vga_controller bus_master cap_list rom configuration: driver=i915 latency=0 resources: irq:46 memory:f7800000-f7bfffff memory:e0000000-efffffff ioport:f000(size=64) *-usb:0 description: USB controller product: Panther Point USB xHCI Host Controller vendor: Intel Corporation physical id: 14 bus info: pci@0000:00:14.0 version: 04 width: 64 bits clock: 33MHz capabilities: xhci bus_master cap_list configuration: driver=xhci_hcd latency=0 resources: irq:44 memory:f7c00000-f7c0ffff *-communication description: Communication controller product: Panther Point MEI Controller #1 vendor: Intel Corporation physical id: 16 bus info: pci@0000:00:16.0 version: 04 width: 64 bits clock: 33MHz capabilities: bus_master cap_list configuration: driver=mei latency=0 resources: irq:47 memory:f7c1a000-f7c1a00f *-usb:1 description: USB controller product: Panther Point USB Enhanced Host Controller #2 vendor: Intel Corporation physical id: 1a bus info: pci@0000:00:1a.0 version: 04 width: 32 bits clock: 33MHz capabilities: ehci bus_master cap_list configuration: driver=ehci_hcd latency=0 resources: irq:23 memory:f7c18000-f7c183ff *-multimedia description: Audio device product: Panther Point High Definition Audio Controller vendor: Intel Corporation physical id: 1b bus info: pci@0000:00:1b.0 version: 04 width: 64 bits clock: 33MHz capabilities: bus_master cap_list configuration: driver=snd_hda_intel latency=0 resources: irq:48 memory:f7c10000-f7c13fff *-pci:1 description: PCI bridge product: Panther Point PCI Express Root Port 1 vendor: Intel Corporation physical id: 1c bus info: pci@0000:00:1c.0 version: c4 width: 32 bits clock: 33MHz capabilities: pci normal_decode bus_master cap_list configuration: driver=pcieport resources: irq:16 *-pci:2 description: PCI bridge product: Panther Point PCI Express Root Port 5 vendor: Intel Corporation physical id: 1c.4 bus info: pci@0000:00:1c.4 version: c4 width: 32 bits clock: 33MHz capabilities: pci normal_decode bus_master cap_list configuration: driver=pcieport resources: irq:16 ioport:e000(size=4096) ioport:f0000000(size=1048576) *-network description: Ethernet interface product: RTL8111/8168B PCI Express Gigabit Ethernet controller vendor: Realtek Semiconductor Co., Ltd. physical id: 0 bus info: pci@0000:03:00.0 logical name: eth0 version: 09 serial: 60:a4:4c:57:98:ab size: 100Mbit/s capacity: 1Gbit/s width: 64 bits clock: 33MHz capabilities: bus_master cap_list ethernet physical tp mii 10bt 10bt-fd 100bt 100bt-fd 1000bt 1000bt-fd autonegotiation configuration: autonegotiation=on broadcast=yes driver=r8169 driverversion=2.3LK-NAPI duplex=half firmware=rtl8168f-1_0.0.4 03/27/12 ip=192.168.1.50 latency=0 multicast=yes port=MII speed=100Mbit/s resources: irq:45 ioport:e000(size=256) memory:f0004000-f0004fff memory:f0000000-f0003fff *-pci:3 description: PCI bridge product: 82801 PCI Bridge vendor: Intel Corporation physical id: 1c.5 bus info: pci@0000:00:1c.5 version: c4 width: 32 bits clock: 33MHz capabilities: pci subtractive_decode bus_master cap_list *-pci description: PCI bridge product: ASM1083/1085 PCIe to PCI Bridge vendor: ASMedia Technology Inc. physical id: 0 bus info: pci@0000:04:00.0 version: 03 width: 64 bits clock: 33MHz capabilities: pci subtractive_decode bus_master cap_list resources: iomemory:202001f10-202001f0f *-usb:2 description: USB controller product: Panther Point USB Enhanced Host Controller #1 vendor: Intel Corporation physical id: 1d bus info: pci@0000:00:1d.0 version: 04 width: 32 bits clock: 33MHz capabilities: ehci bus_master cap_list configuration: driver=ehci_hcd latency=0 resources: irq:23 memory:f7c17000-f7c173ff *-isa description: ISA bridge product: Panther Point LPC Controller vendor: Intel Corporation physical id: 1f bus info: pci@0000:00:1f.0 version: 04 width: 32 bits clock: 33MHz capabilities: isa bus_master cap_list configuration: latency=0 *-storage description: SATA controller product: Panther Point 6 port SATA Controller [AHCI mode] vendor: Intel Corporation physical id: 1f.2 bus info: pci@0000:00:1f.2 version: 04 width: 32 bits clock: 66MHz capabilities: storage ahci_1.0 bus_master cap_list configuration: driver=ahci latency=0 resources: irq:43 ioport:f0b0(size=8) ioport:f0a0(size=4) ioport:f090(size=8) ioport:f080(size=4) ioport:f060(size=32) memory:f7c16000-f7c167ff *-serial UNCLAIMED description: SMBus product: Panther Point SMBus Controller vendor: Intel Corporation physical id: 1f.3 bus info: pci@0000:00:1f.3 version: 04 width: 64 bits clock: 33MHz configuration: latency=0 resources: memory:f7c15000-f7c150ff ioport:f040(size=32)