Thank you for this post, I was crazy finding some solution to our common problem, Great Work!

Thank you, it works

I too had this issue, and to solve it I had to take 2 more steps: Change the value on the option "Hard Disk - Turn off hard disk after" to "never" and Disable my DVD Driver (it seems that it is failiing badly).

Thank you for the post -

I had this issue after reinstalling windows 7 on an Asus Maximus V Gene (Intel Z77) mainboard. I might not have had the IRST installed before, but now I do since reinstalling, I have this problem.

I have an SSD installed for the operating system, but the system hang only occurred when trying to access a regular harddisk. Windows would respond normally (I could find this website for instance), but the explorer window where I was browsing the second harddisk would hang. As soon as I made the change in power settings, the explorer window snapped out of it and the file I had clicked inside it opened.

I''ll keep an eye on the IRST software to make sure it doesn't change the value back to power saving.

I had same issue with HP server running backup from unix OS, the server is 2008 R2 enterprise. When we are running full backup its getting failed one of the server which is running this OS. We change the power settings as its mentioned but still we are having the same issue. Backups are keep on failing. Pls suggest

I had to turn off Link Power Management in both the Intel Software (requires a reboot) and in the Windows Power Management settings show above. I have a Samsung 840 Pro SSD.

Actually, this is the incorrect setting for your issue! (That setting only affects purely PCI Express devices, such as Graphics Cards) It is actually the "AHCI Link Power Management - HIPM/DIPM" Power Options setting which is changed from HIPM (Balanced) to Active (High Performance). This setting, by default, is HIDDEN inside of the advanced power settings menu. In order to expose it (as well as transition time setting from "Partial" hard disk state to "Slumber" hard disk state; "AHCI Link Power Management - Adaptive"), you must go inside the registry to both:
1. HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Power\PowerSettings\0012ee47-9041-4b5d-9b77-535fba8b1442\0b2d69d7-a2a1-449c-9680-f91c70521c60 and change the "Attributes" key value from 1 (default; hidden) to 2 (exposed). [This will expose "AHCI Link Power Management - HIPM/DIPM" under Hard Disk power settings]
2. HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Power\PowerSettings\0012ee47-9041-4b5d-9b77-535fba8b1442\dab60367-53fe-4fbc-825e-521d069d2456 and change the "Attributes" key value from 1 (default; hidden) to 2 (exposed). [This will expose "AHCI Link Power Management - Adaptive" under Hard Disk power settings]

BE VERY CAREFUL YOU DO NOT MODIFY ANYTHING OTHER THAN THESE EXACT ABOVE TWO REGISTRY SETTINGS! YOU CAN RENDER WINDOWS INOPERABLE IF YOU DON'T KNOW WHAT YOU'RE DOING! Changing the "Attributes" key values from 1 to 2 are completely safe! All this does is changes the setting boxes from Hidden to Exposed. The settings themselves DO NOT change unless you change them inside of Power Options. (Either by way of switching performance profiles and/or changing advanced power settings through Power Options)

Please refer to this wonderful explanation of the above settings, as well as a downloadable .reg file to automatically change the above "Attributes" values SAFELY for you:
http://www.sevenforums.com/tutorials/177819-ahci-link-power-management-enable-hipm-dipm.html

READ THE RED BOX!
"WARNING: Your SSD and HDD drives must support HIPM and DIPM, and must have a SATA connection with AHCI mode enabled in the BIOS for them to be able to have their power usage managed.
AHCI is usually enabled in the BIOS by you before installing Windows 7. If you didn't, then you will need to enable AHCI after the installation of Windows 7 before doing this tutorial."

In order to easily check whether or not your Hard Drives support HIPM, DIPM, and/or HIPM+DIPM, you can download AIDA64 from http://www.aida64.com
Please note: They are only "Trial versions", but they are fully functional and will allow you to see which, if any drives, support the above advanced power management features for HDDs/SSDs.

(HIPM = Allow Host-initiated Interface Power Management; DIPM = Allow Device-initiated Interface Power Management; HIPM+DIPM = Allow Both Host-initiated AND Device-initiated Interface Power Management; Active = Do NOT Allow either HIPM or DIPM)

Hope this helps =D
-Erik

Confused about the final settings to choose. Are these the settings to use to address the problem?
(HIPM = Allow Host-initiated Interface Power Management; DIPM = Allow Device-initiated Interface Power Management; HIPM+DIPM = Allow Both Host-initiated AND Device-initiated Interface Power Management; Active = Do NOT Allow either HIPM or DIPM)
Thanks.

I discovered the correlation between the periodic system hang and the Event ID 129 log entry on a HP Envy Notebook running Windows 7. Turning off Link Power State Management seemed to fix the issue. When I found this blog entry, I considered it the confirmation I needed. So thanks for posting and for all the good comments too.

I discovered the correlation between the periodic system hang and the Event ID 129 log entry on a HP Envy Notebook running Windows 7. Turning off Link Power State Management seemed to fix the issue. When I found this blog entry, I considered it the confirmation I needed. So thanks for posting and for all the good comments too.

A Windows Server 2012 was performing so bad that applying this solution took me 1 hour to get the events out of the eventlog and 1,5 hour to apply your solution. It solved the problem perfectly. Thanks.

Oh my god. thank you, this solved my problem.

This resolved my issues. Thanks!

Turning off LPM in the Intel RST had no effect. I had resets of the bus every 30 seconds (including a strange sound from the CD rom). But turning off the PCI-express energy option shown here has helped to have a quite system again. Thanks a lot!