These hidden partitions can be a real pain. It is one of the reasons I'm not keen on products that install hidden partitions (such as Acronis). Most people either do not realize they are there. They also take up valuable space on the HDD. If the Dell partition just contains diagnostic test utilities....then IMHO, it would have made sense to just provide a CD instead.
Just so you know, the Vista BCD, more so since SP1, seems to get 'corrupted' relatively easily. It's not that it contains garbage, it is just that some of the entries are screwy. I think it just tries to be too clever for its own good.
Anyway, my guess is that you backup only included the Vista partition - the useful part - but did not include the hidden partition. If that is the case, then there is a chance that the Vista BCD has some incorrect entries relating to the hidden partition that no longer exists. I guess it could also be possible, though less likely, that the Partition Table has the wrong partition marked as Active.
You could take the "simple" approach: Boot SP CD, backup all partitions, including the pesky hidden partition, and then restore the whole lot back to the new drive. For restore options, you will need to restore the original MBR. For Vista, you will probably need to restore the Disk Signatures.
Considering your lengthy restore, I'd choose the alternative option: Run the normal mbr fix, boot fix and rebuild BCD. In your case, I think the MBR boot code and boot sector are just fine. Running the repair shouldn't cause any problems, though.
If you know what you are doing, you can boot into the SP CD and edit the BCD and/or Partition Table manually......However, the safer option might be to do the following:
Boot the PC with the Vista install CD and select the Windows Recovery Environment (RE).
- Select System Recovery Options*
- Select the Command Prompt
- Type the following commands:
bootrec.exe /FixMbr
bootrec.exe /FixBoot
bootrec.exe /RebuildBcd
The final command will search the HDDs for Vista compatible OSs and ask whether you want to add them to the BCD database.
* Microsoft normally recommends that you run the "Startup Repair" first, but in your case I do not think that will fix the problem, though you can give it a whirl.