Question : Problem: Restored deleted/missing files now getting errors when trying to open them.

A directory was deleted or went missing on a server of a client of mine.  I restored the files with active undelete 7.0.  Now that they are restored, none of the files will open.  Some excel and word documents are giving me an error "Cash balance 2008 is not a valid single web page".  Other ones like word are opening and just giving me boxes and symbols as text.  THIS INFORMATION IS EXTREMELY IMPORTANT its all financial data from 2008.  My backups wont mount that is why i used active undelete software.  The software has worked good for me in the past im just at a loss now.

Answer : Problem: Restored deleted/missing files now getting errors when trying to open them.

Yip sounds like the files are corrupt, after the restore.
Were the files on a Windows server?
Check if you've got Volume Shadow Copy enabled on that volume?
You could possibly restore it from there.
NB Volume Shadow Copy should not be considered and alternative to a decent backup system.