One of the compelling reasons I tell customers and friends for upgrading from Windows XP to Windows Vista is the extremely easy to use yet powerful backup feature. All it takes is three clicks to backup your entire computer to a removable USB storage or DVDs. You can backup a partition or folders to another partition. And the entire backup procedure for few hundred gigabytes of files takes less than an hour the first time itself, after that the incremental backup get done in minutes. The best part is that the backup is stored in VHD (Virtual PC format) format, which is a fully documented and free to use file specification. This means even if Microsoft restore utility is unable to open the VHD file, some 3rd party utility may be able to open it. I have been using the backup feature for nearly a year and I am very pleased with it. Recently when I had trouble with Windows in my Home PC, I restored my backup that was taken few months back – the entire restore process worked flawlessly and my Windows installation was good as new. 
Today before I did a routine backup of my Home PC, I wanted to clear some space in the external USB drive. I deleted all the previous backup files in the drive. Then I ran the complete back up. Unfortunately after several minutes the backup utility failed with the following strange error.
The backup did not complete successfully. An error occurred. The following information might help you resolve the error:
The system cannot find the file specified. (0x80070002)
I tried doing Vista Disk cleanup, no use. Doing few Internet searches with the error number 0x80070002 I found a forum post that talked to clean up registry keys in HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\ProfileList that pointed to orphan profile paths. I checked that, in my case all the profiles had correct paths. So that was not the problem. Then one of the forum post talked about running Chkdsk on the drives, I did that. Rebooted the machine. Tried the backup again, this time it went smoothly.
Now my love is back for the Vista Backup tool. I just wish Microsoft wrote the backup utility a little bit more tolerant or instructive error messages for handling these occasions.
Lambert, I couldn’t agree more with you on the High-Stress activities and backup/restore is certainly High-Stress.
Hope Microsoft is listening to these customer feedback and will improve the error messages to be more user-friendly. The error messages in my opinion should not be about reporting items or logging issues, but they need to give guidance to user on what to do next. With Internet connection I am sure this is possible, the software can connect to the cloud, to see similar patterns and come up with recommendations. Just like how Windows Update today works for driver issues and conflicts. Having said this, software should and can become smart enough to self-heal and not require error messages. We need to get to that day.
As we have the next Billion People in the planet taking on to computers, the need for software engineers to make software more user friendly is critical.
Sure, you knew you had a plan-"B" in case something went wrong, but you’re a Microsoft Regional Director — technically elite, and far, far beyond the technical sophistication of the target audience here.
I’m bemoaning the fact that a real "end user" wouldn’t stand a chance when faced with this problem. Now, when it happens on a backup, it’s a problem, but when it happens on a restore, it’s a catastrophe.
Have you ever seen some of the studies that show how people react poorly to small problems in high-stress situations and start making all sorts of really, really bad choices? Next thing you know, they’ve driven a car off a bridge or crashed an airplane or something.
Backup and (especially) restore are inherently high-stress activities. If something goes wrong, the last thing the user needs to see is a cryptic message that doesn’t help them understand what the problem is. Faced with such a message, a user under stress is pretty likely to do something that’s going to make the situation worse, and that’s why I’m being more critical of backup & restore than I would a "normal" application.
Nice and valid points D.Lambert.
To defense of Vista backup, what I did was not a typical step any end-user will do. I was little adventurous when I deleted the old backups from this external HDD before I tried the backup. Anyways I had the documents & user data from that PC copied to another PC in my house, before I ventured into this. So if this backup failed and my PC main HDD failed I would have been left with the need to restart Vista and program installation. The chkdsk incidentally didn’t find any errors with the hard-disk, it was more some index issue I suppose.
Ok, so you deleted all previous backups because you were getting an error on a backup?
What if the error you got was an indication that the HDD was going bad? I’ve had multiple HDD’s fail in exactly this mode, such that doing a chkdsk on the drive is the final injury. You’d have been left with a dead PC and no backup – all because the backup error didn’t actually explain why it was failing.
Unacceptable.
I had occasion recently to back up my PC to an exteral HDD (connected via eSata). Shortly afterwards, the HDD on my PC died, and I needed to restore from my backup. I ran the "complete restore", and a couple minutes into the restore, I got an error very much like the one you described – with *absolutely* no human-readable indication of the problem whatsoever.
My backup was shot. Unacceptable.
After googling this problem with beads of sweat forming on my brow, I finally stumbled on someone who had a similar problem that seemed to be specific to eSata. Sure enough, when I took the same extrnal HDD and connected by USB instead of eSata, the restore worked.
This is not very confidence-inspiring, and that is *not* a characteristic I look for in a backup system.
There’s a lot of work do here before this tool can be considered production-ready.