My laptop: Dell Inspiron N5110 with 2.50 gHz Intel Core i5-2450M processor, 500 GB HDD, 6 GB memory.
OS: Starting from OEM installed Windows 7 Pro (x64), my upgrades to Windows 8, 8.1 and 10 went smoothly with some minor hiccups and my system is now Windows 10 Pro (X64) upgrade to 1511 build 10586 installed on Apr 25, 2016.
Following MS hotfixes have been installed thereafter:
KB3116278 and KB3142588 on Apr 25
KB3140741, KB3147458 and KB 3154132 on Apr 29
Both MBAM and Windows Defender, updated till May 7, do not show any virus activity.
After Dell welcome screen and then a blue screen with Windows icon lasting only 1-2 sec, another blue screen appears with those 6 marbles spinning in a circle! This screen lasts for about 100 minutes (yes, 1 hr. 40 min) and only then I get Windows logon screen. Thereafter, everything (at least those I use mostly) seems to work normally.
Windows 10 latest update is not a culprit as there was no such problem till about April 30, but I do not remember what else I did thereafter.
Through msconfig, when I select "Diagnostic startup", booting takes only a few seconds though many services don't get launched. "ntbtlog.txt" shows BOOTLOG_NOT_LOADED for dxgkrnl.sys and WdFilter.sys. When trying "Selective startup" (default, and even if I select Normal startup, it goes back to default), ntbtlog.txt shows BOOTLOG_NOT_LOADED for dxgkrnl.sys (5 times, though once under BOOTLOG_LOADED), WdFilter.sys (twice), NDProxy.sys (4 times), and Condrv.sys (once).
Through EventViewer > Windows logs > System, I found that out of nearly 100 minutes' boot time, about 95 minutes were due to Error from source "Service Control Manager" (event ID 7023) appearing every 5 minutes and the event description showed "The Microsoft Passport Container service terminated with the following error: General access denied error".
The aforesaid display was interspersed with Warning event IDs 1, 28 and 414 and Error event IDs 7031, 10010 and 10016.
I tried to restore to the only earlier point of May 3, but the problem essentially remained the same.
If you have any suggestion, please spell it out step-by-step as I'm not very computer savvy.