Have had a perfectly working i5-2500k powered Windows 7 Pro 64-bit oc'kd to 4.3GHz for months now, until last night when I uninstalled the new crap Firefox Quantum with the intention to revert to the older Firefox 54.

Upon re-boot, I got the expected  POST beep, and got the BIOS splash screen, the got to the logon screen, but after that all that displayed was the mouse arrow and black screen. After re-booting again and getting an overclock failed flag on the POST screen, through the Asus BIOS, I went back to default settings, but still nothing other than that mouse arrow despite leaving the PC on for hours, re-seating the 8Gb OCZ RAM sticks. Initially I thought maybe the CPU had died due to the oc'k, but logic tells me why would the Windows logon screen show up.

Any ideas? Please assist, if possible or is it an OS re-install?

 

Hi Rick,

Don't begin OS reinstall yet as it could be something as simple as  A "SecureBoot Violation" in Win7/64 preventing ASUS UEFI bios from booting into the OS. There is a fix / workaround from ASUS that you enter the bios with Del or F2 to enter UEFI, bios navigate to "Boot" tab choose "other" where Boot/SecureBoot may currently be set to "Windows UEFI Mode" the workaround solution is to set for "OS Type"  set it to "Other OS" Then press F10 to save changes and reboot. Re enter the Bios and check Boot tab Secure boot Platform Key (PK) State" is switched to be "Unloaded". Change accordingly and press F10 to save and reboot. Your OS should boot normally now.

("Quote")

FAQ

Why does the “Secure Boot Violation” appear when I enter my WINDOWS 7 OS?

Last Update : 2017/09/28 19:47

 

After installing Microsoft Update KB3133977 for Windows 7, some users may encounter a "Secure Boot Violation" , which makes the system fail to boot into the operating system.

 

To protect user's systems from malware attacks, ASUS motherboards implement the Microsoft Secure Boot feature by default. This feature performs a legal loader check to boot into the OS. As Windows 7 does not support Secure Boot (https://technet.microsoft.com/en-us/library/hh824987.aspx), with the update of KB3133977, the system might detect inconsistent OS loader keys, resulting in boot failure.

Please change UEFI Secure Boot settings as outlined in the steps below, this will allow the system to boot into the operating system successfully.

Step 1: Press Del or F2 to enter UEFI BIOS setting

Step 2: Enter the UEFI Ez Mode, then press F7 to enter Advanced Mode

Step 3: Enter the Advanced Mode Menu->Boot->Secure Boot

Step 4: Change “OS type” to “Other OS”

Step 5: Press F10 to Save the changes and reboot

Step 6: Check the UEFI Advanced Menu->Boot->Secure Boot, and confirm whether the “Platform Key (PK) State” is switched to be “Unloaded”.

Step 7: Exit the UEFI, and the system will now boot normally.
 

Incidently - Win 10 supports Secure Boot,  it only happens in W7 because 7 does not support ASUS SecureBoot facility.

Here is a description of "Secure boot violation" preventing OS boot" in W7 where Win update (KB3133977) has been installed - from the source at ASUS  FAQ's:

https://www.asus.com/support/faq/1016356
 

Edited July 15, 20187 yr by Jethro

If Jethro's suggestion doesn't work, take a look at https://answers.microsoft.com/en-us/windows/forum/windows_10-performance/windows-10-black-screen-with-cursor-after-login/1d471d5f-c88e-4f0a-b69f-1676b369f2dc and https://www.drivereasy.com/knowledge/fix-windows-10-black-screen-with-cursor-error/ (the comments have a lot of good info).

Out of interest, what problems did you have with Firefox Quantum? For me, it's been the best browser I've tried so far.

Edited July 16, 20187 yr by vortex681