Nothing to correct - this is exactly as it should be in Windows 7 which always itself as C when booted.
Most drivers are in installer with newer delivered quickly via optional Windows Updates.
Any drivers then missing in Device Manager can be found on the Toshiba Support Downloads webpage for your model, or click Update Driver in Device Manager, then browse to the D:/Windows/System32/Drivers and /driverstore folders to see if it will pick up driver from there. Driver Install - Device Manager
Check the activation status at Computer>Properties. You can insert the Home Premium Product Key on COA sticker there to activate with the license which came with computer.
May I ask why you upgraded HP to Pro and then Dual Booted a new HP install?