Convert MS Office 97-03 to MS Office 2007

What is the best way to properly and easily "batch" convert MS Office 97-03 files (*.doc, *.xls and *.ppt files) to MS Office 2007 xml?

Someone I know had major issues doing this. They said that it may have been better to have opened each file individually and then save each file to the new format.

They used MS OFC tool (it’s part of their OMPM package) together with the MS Office Compatibility Pack for the conversion. This caused some major issues.

Thanks in Advance.