(imported comment written by NoahSalzman)
You can certainly grab the SHA1 of a file and store it somewhere. We generally advise against scanning all the files on a disk. Are you looking for a particular set of files to scan?
In any case, here is a simple example.
q: (pathname of it, sha1 of it) of files of folder “c:\windows”
A: c:\windows\bfsvc.exe, f8be945bc873ba28720bb9dea01b7b9b36a471f6
A: c:\windows\bootstat.dat, bbdd06e7e944e8e72dd820ea4e8b0ff45796480f
A: c:\windows\certutil.log, 7c97aba99be83a83016316e455016bf47a7f213e
A: c:\windows\DtcInstall.log, 5dface5aaed125bce5ed5a2919d0d0454ab4f55a
A: c:\windows\explorer.exe, 4b3bd605b63749ff255e048ca6f27aff95aec24a
A: c:\windows\fveupdate.exe, 2ab2f12c0ec5ca452c63a4a59d55d6a03b4b498b
A: c:\windows\HelpPane.exe, fb2b64805e8ef1afa11439589a172603a881dd3f
And, if you are looking for checking hashes from a known list of files here is a related post:
http://www.ibm.com/developerworks/forums/thread.jspa?threadID=418040