go to start /run type in calc.exe ,see if you calculator still works ,
sooy i don't know what you were using to record unless it was just the windows recorder,in that case type this ,sndrec32.exe into run and see if its still installed .
If they are installed and working come back and i will show you how to put them back in accessories .

If they are not still installed go to control panel ,add and remove programs and on the left side add.remove windows components ,click it open accessories and utilitys ,details /accessories, click details again and check to install calculator .if its install check to uninstall ok you wat back out then go back in and reinstall it .
I looked around in there and can't see the recorder install