eloise

I have run chkdsk, is that what you mean? It was clean. I cannot run sfc scannow, as I have no installation disc for the operating system, but it is genuine....was installed by a PC World technician. I have also set up Dr. Watson to trap user-mode program errors, as per instructions in the Microsoft article.

Might have been coincidental. I use CCleaner on a daily basis - has never happened before. Also had another unrelated BSOD recently. Was about to shut down the computer last night, only CCleaner was running - it happened half way through cleaning? Bug check: 0xc000021a https://onedrive.liv...C6FEC3EF3C7!105 "The STOP 0xC000021A error occurs when either Winlogon.exe or Csrss.exe fails. When the Windows NT kernel detects that either of these processes has stopped, it stops the system and raises the STOP 0xC000021A error. This error may have several causes. Among them are the following: Mismatched system files have been installed. A Service Pack installation has failed. A backup program that is used to restore a hard disk did not correctly restore files that may have been in use. An incompatible third-party program has been installed." http://support.micro...om/kb/156669/en I've not installed any new programs or drivers and I've also run a number of malware / rootkit scans in case - MalwareBytes, TDSSKiller, Hitman Pro and McAfee Stinger - no threats found. Any ideas please?