None of the above recommendations worked
You marked an answer as accepted. Did that fix your problem or not?
The title of this question matches your problem description.
https://answers.microsoft.com/en-us/windows/forum/all/task-scheduler-service-is-not-available-task/cd3b2be4-4206-4ae1-81dd-ef29e3bc9ae1?page=1
In that post user CaliDogg7 replied that he solved the problem by deleting an empty task file that he found.
Open Powershell_ISE with "run as administrator" and run this script. See if it detects a mismatch or an empty file.
$files = Get-ChildItem C:\Windows\System32\Tasks -file -Recurse
"File count = {0}" -f $files.count
$tasks = Get-ScheduledTask
"Task count = {0}" -f $tasks.count
if ($files.count -ne $tasks.Count) {
$t = $tasks.taskname | Sort-Object
$f = $files.name | Sort-Object
""
"Here is whats different."
Compare-Object -ReferenceObject $f -DifferenceObject $t
}
$sm = $files | Where-Object -Property Length -lt 1000
if ($sm.count -gt 0) {
""
"Here are the small files."
$sm | ft -Property Length, FullName
} else {
""
"No small files detected."
}