It's not working when I type chkdsk /f /r . It says "the parameter is not valid. Try /? for help." So I did chkdsk /f /? . It reported back "chkdsk [drive:] [/p] [/r]" and tells me what those 3 do. Below that it says "chkdsk may be used without any parameters, in which case the current drive is checked with no switches. You can specify the listed switches."
"chkdsk requires autochk.exe file. Chkdsk automatically locates autocheck.exe in the startup (boot) directory. If it cannot be found in the startup directory, chkdsk will attempt to locate the windows installation cd. If the installation cd cannot be found, chkdsk prompts for the location of autochk.exe."