Sidebar disappeared

The Vista sidebar suddenly gone, along with all the gadgets. It doesn't show
up at startup, it refuses to start manually, it doesn't appear at the system
tray, it's not on the processes list. I was unable to delete settings.ini
located at Program Files\Windows Sidebar, neither by pressing delete, nor by
using Unlocker. I don't use System Restore (there are several reasons for
that). I've seen some people complaining about similar problem on some other
MS forums, but no one gave any useful advice.
Using Vista Home Premium x86, all updates installed.
Does anybody know what should I try? Thanks in advance.

Start | Search | Sidebar

Click on Windows Sidebar in the top pane.

Happened to me; had to start it from it's directory with run as admin even
thought my logon was in the admin group. Problem turned out to be the defrag
option of a registry cleaner. Fix was to restore registry.

I've also had this problem for the last few weeks, though happily I fixed it
today.

This was in part with a call with MS support, and in part watching what
sidebar.exe was doing with Procmon. I'm not certain that my reasoning is
correct below, but you may get some mileage from it.

I suspect that an application had installed a duff copy of atl.dll (in my
case I think it was from HP's IPaq Choice Points program - as procmon showed
a reference to an HP directory when sidebar tried to start up).

I uninstalled the HP program to be sure. In the same way you may wish to
search your machine to see if you have multiple copies of atl.dll before
starting.

Upon the advice of MS support, I unregistered a couple of sidebar DLLs. This
took me a little while as I didn't realise the DLL's are in Program
Files\Windows Sidebar directory (windows search never found them for me,
which is a touch annoying). Anyway to do this bit:

1. Start an elevated privileges command prompt
2. cd "\Program Files\Windows Sidebar"
3. regsvr32 -u sbdrop.dll
4. regsvr32 -u wlsrvc.dll

I then tried to re-register them, but it wouldn't work - I just got an error
message. After some hunting around, I decided to first register (re-register
?) ati.dll. I didn't try to unregister it first, and as I definitely only
had one ati.dll now, I didn't have to go looking for it to check I had the
right one - but you might have to. I don't know what will happen in you
unregister ati.dll so be warned.

So the next bit as I did it is:

1. From the same elevated command prompt (still in the C:\Program
Files\Windows Sidebar) directory
2. regsvr32 ati.dll
3. regsvr32 sbdrop.dll
4. regsvr32 wlsrvc.dll

With the ati.dll done first, the Sidebar DLLs registered fine. Then I tried
to start sidebar.exe again and it came up fine.

I had over previous weeks deleted all the sidebar settings and such like in
an attempt to get it working, so I guess that might still be necessary as
well - but my feeling is that it's really to do with the dll's above and the
settings removal isn't important.

Hope it

shouldn't that be, cd "c:\Program Files\Windows Sidebar"
My sidebar dissappeared also and i didn't work with the previous path.
Only when i typed in this path: cd "c:\Program Files\Windows Sidebar",
i managed to get to step 3

[sharee100]

for solution see top line above...START/ In the START SEARCH box type SIDEBAR. Click on the WINDOWS SIDEBAR program at the top of the list. Voila! Sidebar reappears. Thank you to Richard Urban for such a brilliant and simple solution. I went to Microsoft support site and got an answer that no one would be able to follow.