This isnt an authoritative answer Ive just had this problem, sifted through the initial bogus media coverage, found a solution, and started speculating on the real cause. Heres a workaround for the problem, though this company mis diagnosed the problem it wasnt an ACL problem. This fix is opaque and comes from a third party, but it fixed the problem for me http www. Black Screen woes could affect millions on Windows Vista and XP. Editorial Novaro Pdf'>Editorial Novaro Pdf. Note their fix is an exe and they dont tell you what it does. I appreciate that they are helping, but they should fully disclose their fix so at least advanced users can have confidence in their good intentions. Heres a better possible reason for why the problem occurred a registry key telling Windows which shell to run on login was corrupted a REGSZ key was missing a 0. Sounds somewhat plausible, but the fishy part is what caused that http www. Windows 7 Loader is a program developed by Daz crew to programmatically activate most of the Microsoft products such as Windows 7, Windows 88. Windows 10, Office. Windows Black Screen Root Cause. My symptoms observations I ran into this problem on a Win. Windows Vista Ultimate. I log in, get a black screen, and Windows never proceeds to setting up my desktop, etc ie, Windows never launches explorer. Running the fixing tool from Prevx did solve the problem, however their diagnosis for the cause of the problem was wrong their initial hypothesis was the ACLs were incorrect and implied Windows Update patches broke it, but that was wrong. They followed up with the non null terminated string hypothesis. Before running Prevxs tool, the registry key existed, Reg. Edit visually displayed the expected value explorer. ACLs were fine.   Yet, of course, I couldnt successfully log in. My pure speculation about the cause So if the missing 0 hypothesis is correct, and if the Prevx tool deletes recreates the value in the registry key, obviously that should fix the problem. FYI look at the MSDN docs for Reg. Set. Value. Ex for a note about the lp. Data parameter needing a 0. But that doesnt explain how the value got messed up in the first place  I dont go around removing terminating zeros from REGSZ values for fun nor profit. Sounds like either random corruption, or more likely, something wanted to run something when Windows boots then incorrectly undid their change to the registry. I saw that some MS security folks suggested this could be caused by malware http blogs. Barbara Corti Flos. Since 2017 Barbara Corti is the Chief Digital Officer of Flos, graduated in Architecture, she has been working for more than 10 years as Creative. Windows 10 Final All Edition Activator KMS Auto Lite For Pro,Enterprise All is a working activator for all edition of microsoft windows 10, which is most using. Get help, support, and tutorials for Windows productsWindows 10, Windows 8. Windows 7, and Windows 10 Mobile. ReLoader Activator 1. RC9 Windows Activator can give you more help in all windows Activation. Enjoy with Full Free version of Final Activator for Office. Microsoft Toolkit 2. Office Windows Activator Download Microsoft Toolkit is a multifunctional based KMS activator which works for the operating. Download the free trial version below to get started. Doubleclick the downloaded file to install the software. Operating under that hypothesis, I ran Forefront on Wednesday using the current signatures, but it didnt report anything. That may not spot a novel virus or rootkit, of course. 91 Pc Suite For Android. Another wild guess perhaps the act of installing certain classes of patches could cause the problem, due to a hypothetical bug in Windows Update. Windows Update does something on boot up to configure patches, and it looks like this happens after login but before Explorer is running. Perhaps Windows Update itself could be editing this registry key to replace the shell with another program that configures patches or options to explorer. If thats how it works which is a big guess, then maybe when WU restores the registry key value to explorer. Vqvk9Xwm9fQ/UO2FQkATwpI/AAAAAAAAAFQ/S3Fax-skS2o/w1200-h630-p-k-nu/MS_Office_2007_Logo.svg.png' alt='Microsoft Office 2010 And Enterprise Activator Updated October 2' title='Microsoft Office 2010 And Enterprise Activator Updated October 2' />Win. Of course, I would have expect to see a bad value for this reg key in Reg. Edit if this were the case. I didnt perhaps there were some unprintable characters in the string, or Ive empirically shot down my own wild guess. Note my problem occurred on a Windows 7 Ultimate machine that was upgraded from Vista Ultimate. Perhaps something during upgrade may have introduced some registry corruption that didnt show up until another value in the registry was changed later  BTW, to confirm the fix narrow down this fix, perhaps someone w a broken machine can reboot into Safe Mode, run Reg. Edit, delete HKEYLOCALMACHINESoftwareMicrosoftWindows NTCurrent. VersionWinlogonShell then recreate the Shell key as a REGSZ key, with the value explorer. If that works, that could help confirm the cause and allow us to give standalone instructions for a fix that we can have more confidence in as opposed to telling people to run an exe from a third party.