Windows 7 - Reactivating after upgrading Hard Drive?

This re-activation process has me saying over and over and over "this is why people buy Apple..... this is why people buy Apple".
I have a perfectly legitimate Windows 7 Professional license and installation, but it was on a tiny hard drive. Bought a 500gb hard drive, cloned the sytem [that was not easy... btw], and went to Activate windows 7. It will not activate.
Called microsoft [that was not easy]. their assumptions [automated robot] are wrong... my "activation window" displays no "digits".

anyone successfully done this?

It should work perfectly fine, your key is locked into your motherboard and cpu, not your hard drive. Customer Support didn't help you at all?

What's the specific error you're encountering?

This is the exact same thing that has happened to me,had a 80gb hard-drive full,so upgraded to a 350gb hard-drive reinstalled windows 7 and now my product key wont activate,the error i get is this key has been blocked by microsoft,but the key is a geniune retail one and it passes all validation tests if i put my other hard drive back in,suppose i will have to phone microsoft.

Richie hit it perfectly.

This is all true: because I have worked in the industry specifically on the big vendor side [servers etc] with os volume licensing, I really pressed hard for a solution with Microsoft yesterday. I spent 4 hours of my time that I should not have had to spend [and it cratered my work day], and spoke with a total of 8 people at [or claimed to be] Microsoft including some manager guy in the Volume Licensing department.

they have a technical issue and they are taking no steps to resolve it. The bottom line is to kick it back on the customer. The last rep I spoke to, a Tech Support guy for Windows 7 specifically, said, in essence, that its unresolved. I specifically insisted that he mark my trouble case as "not resolved" and he agreed to do so.

The volume licensing guys take the moral high ground. They want to see the system technically produce the string of digits known as the "Install Key" [nine fields of 5]. But in a Volume License case the security step will not allow that stage to be generated. That is essentially what the error code means. Their intent is that the original server that "sprayed" the OS must also be the server that once again permits the activation.

The Tech Support guy [actually all of them] does not effectively understand what "upgrades" will trigger this condition. I had to stop them all and correct them when they would spout the "party line" about any/all hardware changes being subject to a re-activation. That is not true. most components can be changed, no sweat. Apparently only the mobo or hard drive are the "culprits".

MS is in a vulnerable spot here. They effectively deny a legitimate license holder the rights that the licensee is contractually entitled to. I'm asking a lawyer a question about this. With the right approach, MS will have to change something. Either change the portability clause of the license legalese [big ramifications] or change the security step technically, or come up with an authorized way to "convert" the license to a different type, and issue different code or patch to effect the change [best option].

I would still like to technically work around this. No person at MS, after some checking, tried to accuse me of lying or thievery or anything... they all acknowledged my legitimate license [at least that part of the equation "works"]

On retail or factory OEM , try running a Repair Install to reset the hardware signature after changes.

Repair Install resets activation and reinstalls the OS. For some reason this can forward activation to the robocall to trade numbers to refresh the hardware signature in MS activation servers, whereas a blunt hardware change without Repair Install can get a rejection.