If you use the command line, then this works well too.
I normally redirect for easy access later so:
C:\>find /I /N "test" C:\temp\* > result.txt
Will show all the files and the line that contain "test" (case-insensitive) for files that are in the c:\temp folder. It will create a file called result.txt with the info.
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C:\>find /?
Searches for a text string in a file or files.
FIND [/V] [/C] [/N] [/I] [/OFF[LINE]] "string" [[drive:][path]filename[ ...]]
/V Displays all lines NOT containing the specified string.
/C Displays only the count of lines containing the string.
/N Displays line numbers with the displayed lines.
/I Ignores the case of characters when searching for the string.
/OFF[LINE] Do not skip files with offline attribute set.
"string" Specifies the text string to find.
[drive:][path]filename
Specifies a file or files to search.
If a path is not specified, FIND searches the text typed at the prompt
or piped from another command.