Windows 8/8.1 slow boot (sudden onset)

Question

Can anyone help with a slow boot problem on Windows 8/8.1, please?  This concerns an Asus Zenbook.  It's about 15 months old, and has always booted very quickly.  Now, all of a sudden, it takes 5 minutes to get beyond the Windows logo screen. 
I have tried all the standard things (clean boot, turn off Asus Fast Boot, etc), up to and including Resetting Windows.  No good: on either Windows 8 or 8.1, it still takes 5 minutes.  I have looked at the Windows System Log, and the delay occurs
right at the beginning of the Boot process.  E.g., on the most recent boot I see as the first 3 entries (note, I'm in Europe, so dates are dd/mm/yyyy, and times are in 24-hour clock):
Information    10/03/2014 19:36:23    Kernel-General    12    None The operating system started at system time ‎2014‎-‎03‎-‎10T19:36:23.490074300Z.
Information    10/03/2014 19:36:23    Kernel-Boot    30    None The firmware reported boot metrics.
Information    10/03/2014 19:40:26    FilterManager    6    None File System Filter 'FileInfo' (6.3, ‎2013‎-‎08‎-‎22T11:38:45.000000000Z) has successfully loaded and registered with Filter Manager.
and you can see the 4-minute gap between the 2nd and 3rd entries.  That's where the delay always comes, though sometimes the "reported boot metrics" doesn't show.
A little later in the procedure I do always get the following warning:
Warning    10/03/2014 19:40:31    Kernel-PnP    219    (212)  The driver \Driver\WudfRd failed to load for the device ACPI\ACPI0008\2&daba3ff&2.
However because that comes later I can't see how it can be causing the problem, and I suspect it's an independent issue.
The machine appears to run normally once booted.  It is protected against viruses by Windows Defender.  I have looked at many posts on this and other fora on slow boot, and tried everything suggested, but none of the solutions have worked. 
I have also looked widely on the web for problems with the File System Filter but nothing relevant comes up.  The machine is under warranty, and could be sent back, but that would be a serious pain so if there is a solution I can implement I would much
prefer to do so.  Thank you for looking at this.
There are no stupid rats, only misguided students

Answer 1

Hi Seglea,
I have exact the same issue as you have! The only difference is the time period the splash screen / logo screen with the dots spinning in a circle hangs / delays / freezes: exactly 120 seconds. You can set your watch to that delay. During these 120 seconds
nothing happens, no HDD LED activity, just nothing. Having passed the 120 s, the HDD LED begins to flicker and the logon screen is displayed 15 s later. 
For the first look at it, I believe that it is a timeout problem. Usually Windows services retry to start after just these 120 seconds (e.g. Software Protection is configured this way, but in my case it does not start although configured as auto delayed).
I believe that the clue is to find out which service causes this delay.
My event logs are exactly the same as yours (without boot metrics), I do also have your WudRfd warning!
When started, the machine operates in a fast and stable way, as if nothing harmful had ever happened.
I do also have an SSD installed as only (system) disk.
In my case the startup screen of the BIOS also stays visible for more than 10 seconds, longer as on any other computer I have had before. I also had problems during installation of Windows 8.1. After the first reboot during OS installation the BIOS POST
screen restarted in an endless loop. I could solve that problem by setting the dedicated internal Graphics memory to less than 1024M, although I own 32 GBytes of RAM.
Nothing helped so far, I permuted my BIOS settings, even Fast Boot or Ultra Fast Boot did not help.
I have installed the latest drivers, I even tried to update the firmware of my SSD, but Intels toolbox told me, that my 3 years old 520 series SSD (never had seen any firmware updates before) was up-to date! Thus Windows 8.1 should handle with it. I also
did a quick analyzation with the tools, but everything was ok.
I just run chkdsk /r /f, as Zigzag proposed, but I had nearly the same problems as you have had:
Chkdsk got stuck at 10 % for 10 minutes then the machine rebooted with the 2 minutes delay and event logs do not show any Checkdisk entry.
In the Applications log, I noticed a igfxCUIService1.0.0.0 sourced entry as the first entry after reboot approximately 2 minutes after the end of the delay: The description of the event-ID "0" from the source "igfxCUIService1.0.0.0" could not be found. Event:
started/resumed which sounds ok. But it says that the component that caused this event, is not installed. (my translation from the German log)
The device manager shows that everything is fine and working well.
Here's my System constellation:
Gigabyte Z77X-UD3H, Intel Ivy Processor i7-3770 with 32 GBytes RAM, Intel 520 Series SSD via SATA 6G, BD Writer from LG via SATA 3G
BIOS F20e with UEFI and Secure Boot enabled (Windows 8.1 did install the GPT partitions):
Fast Boot enabled/disabled doesn't bother,  Intel Virtualization  Technoloy Enabled, VT-d enabled, OS Type Windows 8, Network Stack disabled, Secure Boot Mode standard,  AHCI, USB 3.0 xHCI, Internal Graphics Size now 32M, (didn't bother up
to 512M, 1024M BIOS POST-screen endless loop), Intel Rapid Start Technology Enabled (disabled same effect) => I installed Windows 8.1 with "Intel SATA Preinstall driver For AHCI  RAID Mode" in the F6 mode, as Intel recommended, Marvell ATA Controller
for eSATA (disabling same effect), ErP same effects on dis/enabled.
 Windows 8.1 Pro German. Same effect when with or without LAN connected
I am thinking of Reinstalling Windows 8 with CSM mode without UEFI, but I believe that would not have any effect. Maybe I'll try another system disk for a reinstallation (HDD or other older SSD).
It would be nice if this problem could be solved by the community or by Microsoft, since I am not the only one!
Peter