Western Digital 2 TB HDD won't work

Hello,

I bought the WD 2TB Hard drive and using my Dell laptop with windows 7 I copied and pasted tons of files on it. My laptop and the wifes laptop works fine and the folder just opens up and shows all the file like I want it too. I do not have it password protected.
Now I brought it to another guys house to give him the files. He has an HP laptop with windows 7. When I plug it into his I get a message sayin something about too many password attempts and will not open the drive. I never tried any password and don't have it password protected. I phoned the WD people and they were no help at all. I brought the HDD back home and plugged it in here and both of my computers read the HDD without any problems. What would be the problem on the HP computer?
Any help would be greatly appreciated.
Thank you.