Take ownership of the XP drive to get past those permissions: Take Ownership Shortcut
From either there or the secondary HD pitstop, click Organize>Select All, then drag the collective contents of each sub-folder (Downlloads, Videos, Documents, Music, Pictures) to the corresponding Windows 7 User folder on the lefthand Explorer bar. Hold the left click until it expands and confirms copy location in hypertext, only then release the files.
If you plan to leave the XP files on the secondary HD, sort them into copies of the Windows 7 User folders you create there, then right click each to add to the related Windows 7 Library - Include a Folder - Windows 7 Forums.
As you have a new PC, look over also these steps to get the vastly superior Clean Reinstall - Factory OEM Windows 7
or at least Clean Up Factory Bloatware