Do you have any updates in your SP2010\SharePoint\Updates folder? If so, those may not be getting applied. If there's nothing in there (as I suspect), there's something that's corrupt:
1. Either your download of the ISO is corrupt. SharePoint installed fine but when applying SP1, its failing.
2. Something wrong with your server where it's unable to apply SP1.
Usually a reboot fixes these things, if not, you may need to reinstall Windows Server (or at least run an sfc /scannow).