Hi Merlin_2 and again many thanks.
Much progress at last but first you should know I found "Display notification about every script error" already unchecked.
On Scan Disk at message locked, Ctrl-Alt-Del listed 12 items, none of which had "not responding":
Scan Disk (C)
Quick Launch
Msnmsgr
TaskBaricon
ZIclient
Imapp
Wandadoo_Booster
Rundll
Dkservice
Vptray
Pwrtray
Systray.
So did End Task all but the last two without problem except Quick Launch brought up "Chosen close toolbar window. To add toolbar rt click existing toolbar, point to toolbars click item". No idea what that' all about. Disregarded; no toolbar changes occurred.
OK, WHEN REOPENED SCAN DISK Thorough, IT RAN ROUTINELY AND SCANNED ALL 1,471,000 CLUSTERS IN ABOUT TWO HOURS. NO LOCKING; NO ERRORS.
DELIGHTED TO HAVE IT FUNCTION TO COMPLETION UNINTERRUPTEDLY . Any comments? Would very much like to know which Utility caused the problem and how else to get rid of it. And why it appeared in the first place as never did before.
Cordially, RO
PS: The lone "error" c:\\windows\win 386.SMP: should I delete it when it is shown at Disk Check?