Well I think it's fixed now...I found the answer here:
SIDEBAR.EXE MISSING
This is what I did, I have no clue why it worked though...
Hi JMQ17,
Jeremy M is right...it ought to be reachable from there. If it isn't, you might need to re-register some necessary dll files.
Try this:
1. Click Start
2. Type "CMD" without the quotes
3. Right click cmd.exe and select 'Run as Administrator'
4. In the command prompt the pops up, type the following:
Regsvr32 -u "%ProgramFiles%\Windows Sidebar\sbdrop.dll"
Regsvr32 -u "%ProgramFiles%\Windows Sidebar\wlsrvc.dll"
Regsvr32 atl.dll
Regsvr32 "%ProgramFiles%\Windows Sidebar\sbdrop.dll"
Regsvr32 "%ProgramFiles%\Windows Sidebar\wlsrvc.dll"
5. Reboot the computer.
See if this brings back your sidebar.
I hope this helps!