I was trying to setup a Scheduled Task today on my computer and it was giving a weird error:

Task Scheduler
General page initialization failed.
The specific error is:
0x80090016: Keyset does not exist
An error has occurred attempting to retrieve task account information. You may continue editing the task object, but will be unable to change task account information.

It turns out to be a corrupt file, I had to run:

del "C:\Documents and Settings\All Users\Application Data\Microsoft\Crypto\RSA\S-1-5-18\d42cc0c3858a58db2db37658219e6400_*"

and then recreate all my scheduled tasks. It is a pain, but it works