Quick Search feature is built right into Windows Explorer. More precisely, it is referred to as the Quick Search Box and exists in the upper-right corner of the window. Once you open a folder you can

start typing the first few letters of the filename that you're looking for in the Quick Search Box and the Windows Explorer will immediately begin filtering through the list of files

To turn this on, click the Organize button in any folder, and select Folder and Search Options from the menu.

in the Folder Options screen, click the View tab, and scroll the Advanced settings box down to the bottom. You should see “Automatically type into the Search Box”

Click OK, and you should be able to search in the current folder by just starting to type, for instance you can type calc.exe while in the Windows \ system32 folder, and instantly came up with the right file.