Powershell Select String
See without the CaseSensitive parameter, Select-String would recognize both of the strings as matches.
Example
PS C:\> "Hello","HELLO" | select-string -pattern "HELLO"
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Example
PS C:\> "Hello","HELLO" | select-string -pattern "HELLO" -casesensitive
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Using select string we can get event log
Example
$events = get-eventlog -logname application -newest 100
$events | select-string -inputobject {$_.message} -pattern "failed"
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It depends on the if your allowed to see the event log or see you get following message.