Move files from one folder to another

I have 3 files in ABC folder... Source Path is c:\ABC

I have to move this files into this path C:\ABC\Archive....

I am using FileSystem task specified source and destination variables... but i am getting this error

[File System Task] Error: An error occurred with the following error message: "Could not find file 'C:\ABC'.".

Can I know the reason..

Thanks, Anji