after system restore, new hard drive shows wrong size

That is odd. Can you post a screenshot similar to your last?

here's screenshots of diskmanager after the delete, and of extend volume attempt.

here are some screenshots of both disk manager after the mystery partition delete and of the attempt to extend volume onto unallocated space:

That OEM partition is still there - it must be the first partition on the drive (as it should be) and you misidentified it. That is why I asked for verification of the contents. So I don't know what you deleted. But It should work now from appearances.

Are you right clicking on the C: volume and selecting "extend volume"?

ok, deleted the OEM chunk and re-tried extend, same problem. Yes, clicking C: volume then selecting extend volume. Another screen shot of disk manager:

Well I don;t think you should have deleted either partition without knowing what it was for. I hope the one after C: wasn't significant, and the first partition would have still been useful as a DELL recovery partition now that it was identified as the OEM partition.

So, can you reboot your computer and try again? I am at a loss why you can't extend C: at this point.

Gene

I still have the original 50 gig drive sitting around and that's why i'm deleting mystery partitions at will.

Reboot and same issue < sigh >

Well, it looks like you may not be able to extend a boot partition in Windows 7 with the windows 7 disk management. See for instance:

Extending Boot Partition

where they recommend gparted. I would do some research before pursuing this route.

Gene

Problem solved. First tried Gparted boot cd and that was a waste. Stupid thing was complaining of errors related to "can't find Server X".

Downloaded MiniTool Partition Wizard (www.partitionwizard.com) ... I had to upgrade to Pro version for Merge capability ($29). Selected the 450Gb of unallocated space and did "create partition" which created new drive F:. After reboot, then launched tool again and did merge, with C: and F: and that worked fine.

So I'm thinking I might have been able to get this done with win7 tools by simply assigning a partition to unallocated space, then merge may have worked from Disk Manager. MiniTool Part Wizard was also unable to Merge when I only had unallocated space.