I think I have finally resolved my Vista sleep problem. My solution path
was:
-my HP Pavilion Vista system did sleep properly between May 25th (when I
bought it) and June 13th; after that it began either not going to sleep or
not waking from sleep.
-on June 13th I had attempted to install software to run my HP Scanjet 3970
from a CD in drive E: I thought I had verified that the hardware and
software would run on Vista, but evidently I was wrong; the scanner software
appeared to partially install, but not completely; I subsequently
uninstalled the programs.
-I realized later that one artifact of the abortive installation remained, a
reference to a program called zzzhpsetup.exe
-I found zzzhpsetup in the list of msconfig Startup tab items. After I
unchecked it, and did a reboot, the sleep function started to work ok.
-zzzhpsetup did not show up in a full system search. Its msconfig Startup
Command column showed E:\Setup.exe and referenced
HKLM\SOFTWARE\Windows\CurrentVersion\Run in the registry; however, there is
no recognizable item for zzzhpsetup in RegEdit. Google searches reveal
almost nothing about such a program, although it seems to show up in
peoples' HJT logs. I will just leave this item unchecked in the msconfig
startup list. I would like to remove it from the listing altogether, but
have not found a way to do this (since it does not show up in the registry).
-At this point, I have returned most of my Power Save options to the default
values and the machine is sleep and waking normally. Obviously I don't have
a cause and effect conclusion that zzzhpsetup was the source of the sleep
problem, but on circumstantial evidence, it seems likely.
Thoughts from anyone would be welcomed.