Cloning Windows 7 drive to a newer hard drive lose my activation?

Windows 7 has a built in imaging program, but if switching hard drives I would not recommend Windows 7 built in imaging - use Clonezilla or a program linked below and make sure you buy a bigger hard drive then you currently have.

Create A System Image In Windows 7

After you install and activate Windows 7 create a system image as a backup for your current computer in case you ever need to reinstall it. This will restore your computer to it's exact state when the image was made - that will save you the trouble of having to reinstall Windows 7 and everything currently installed again, and it takes much less time to do.

1.  Click the Start Menu and type "Back Up" then click on Back up your Files. 
2.  In the Control Panel window that appears, Click the blue Create a system image link.
3.  The Create a system image window should pop-up.  Select which hard disk, DVD, or network location you are going to save your system image to.  Click Next to continue.
4.  On the next page check both your System and System Reserved drives.  Once you have selected the drives Click Next to continue. Note: You can select as many drives as you want (if available), but the more you choose to include means the larger the image size will be.
5.  The next window is just a review, make sure everything is correct then Click Start backup to start the process.  This can take 10 minutes or more so patience is required.
6.  After the backup completes, you?ll be prompted with the option to create a system repair disc.  This is a good idea just in case your system has any problems in the future.  Click Yes.
7.  Choose which Disc Recording drive you?ll be using to burn the disc.  Insert a blank CD or DVD to the physical drive and then Click Create disc.

 
How To Restore Windows 7 from a System Image
http://www.howtogeek.com/howto/7702/restoring-windows-7-from-an-image-backup


You can also use a free hard drive imaging program - the two below will have more features, and are better, then Windows 7 built in imaging program. Both enable you to make a boot disk to start the recovery.

Reflect Disk Imaging:
http://www.macrium.com/reflectfree.asp

Paragon Backup & Recovery Free Edition:
http://www.paragon-software.com/home/db-express/download.html

Image Windows 7 And Move To New Hard Drive

Connect the new hard drive as a slave, then partition the new hard drive so it has two partitions (or more if you want) - the last partition being a little bigger then the amount of data on your current hard drive. Also make sure that the partition you are moving Windows 7 to is bigger then the entire size of your current hard drive.

Now make an image of your current hard drive with either of the programs below and save it to the last partition on your new drive. If you have the 100MB recovery partition make sure to include that. Then restore the image to the partition you want Windows 7 installed on - you should set it up the same as your current drive, and you may have to delete/change the partitions you made.

There are many detailed guides on the web if you need more details.

I doubt you'll find it, I don't think it's been published, and if it was, it would probably quickly be taken down. I don't think they want anyone to know exactly what triggers it or how long between activations rings the bells!

There are actually many threads here with that info, and it's easy to find elsewhere. So at the risk of having this post edited:

Each hardware part has a point number assigned to it - if you replace too many and exceed a certain amount of points you will have to reactivate Windows. Don't know the exact number until it will force reactivation, but usually replacing just one part (other then the motherboard) doesn't require reactivation.  Product key information, in the form of the product ID, is sent along with a "hardware hash" (a non-unique number generated from the PC's hardware configuration) to Microsoft's activation system during activation.


Windows Product Activation checks eight different categories of hardware:

    * Processor & Serial Number
    * IDE Adapter
    * Hard Drive Device and VSN
    * RAM Amount Range
    * Display Adapter
    * Optical Drive
    * SCSI Adapter
    * Network Adapter

This is related to the question:

Product Activation keeps users from changing or upgrading their hardware.
Not true at all. Users can change or upgrade their hardware. One of the forms of piracy that Product Activation guards against is hard disk imaging. Not all forms of hard disk imaging are illegal. In the case where a pirate copies data from one PC hard drive to another to illegally run the software on two PCs, Product Activation stops that by forcing the copied software to be reactivated. It does so by comparing the hardware on which it was activated to the hardware on which it is now being booted. If the hardware is substantially different, then reactivation is required. If it is the same or similar, then the software will continue to work. Those who upgrade their PC's hardware substantially may be asked to reactivate. Reactivation for this reason is easy and can be completed by contacting Microsoft to obtain another confirmation ID.