Hibernate and backup functions

For over 6 months I failed to find a solution to why neither Windows 7 Backup, nor the Hibernate function operate correctly any longer on my Dell XPS laptop, even though they both worked until May this year.

Backup fails after approx 10-12% with the message "Cannot find the specified file -  Error 0x80070002.", and hibernate initially responds but within 5-10 seconds goes back to the desktop. All the forum searches revealed nothing that corrected the problems, until today. I found a thread suggesting that the recovery partition on the hard disk is a potential problem so try assigning a drive letter to unhide it.

I assigned drive Z to it, rebooted and this solved both problems. Tested it by reversing the process, and the problems re-appeared.

It seems that a process involved can no longer find a particular file unless the recovery partiton is visible to the system. As a precaution, I have hidden files in the recovery partiton to prevent inadvertent changes.

By assigning a letter to the recovery partition, will this affect a factory reset or system recovery? Does anyone know of a better fix for this problem? I've tried all the usual suspects suggested by the Microsoft trouble-shooting website.