Here is how to properly move a user profile from one install of W7 to another. It is for migrating from a corrupt user profile to a new one, but instructions are very similar for moving from one W7 install to another. There are some files you Should NOT copy over.
Create 2 admin user accounts on the new PC, one will be temporary, log into the temporary account, then follow the instructions.
Locate the C:\Users\Old_Username folder, where C is the drive that Windows is installed on, and Old_Username is the name of the profile you want to copy files from.
Select all of the files and folders in this folder, except the following files:
Click the Edit menu, and then click Copy.
If you don't see the Edit menu, press Alt.
Locate the C:\Users\New_Username folder (not the temporary user), where C is the drive that Windows is installed on, and New_Username is the name of the new user profile you created.
Click the Edit menu, and then click Paste. Confirm folder-file replacements if needed.
(If you don't see the Edit menu, press Alt.)
Log off, and then log back into the regular user account, then you can delete the temporary user account.