It took more to get to the point of coping off Office files then you are mentioning. It would require taking ownership of files under the HP user account to then have file access. Never a good idea when wanting to go back to the original system to change file ownership. Hopefully this was limited to only the pictures folder though I would expect the entire user folder would need to be done.
Flashing cursor indicates the loss of the master boot record. You can get into recovery and run the utilities fixboot and fixmbr to see if you can then boot up.
I don't remember I changed the ownership. Only while opening the user folder, it prompted "You dont have permission to... Continue". I clicked Continue.
When I ran Hard disk test, it gave beep sound showing some error (forgot the error number). When I searched for this error number in internet, many suggested faulty hard disk and replacement as solution.
So I removed the dell hard disk and connected to hp laptop again. I had 3 drives in the hard disk. I could open 2 drives except the original C drive. It showed "Access denied".
Then I changed the ownership to Administrator. No objects are found. So added system and TrustedInstaller objects, gave full control and then changed back the owner to Trusted Installer. I could access the original C drive, no problem. For all the folders, either System or TrustedInstaller is made the owner. (I guessed ownership should be the problem).
But after connecting back the hard disk (really a hard job with dell), the problem does not disappear.
After showing Starting Windows with the Windows icon, it goes to a blank black screen. Now no cursor too.
I have tried safe mode with command prompt, it again goes to a black screen.
Recovery - after taking some input like language - it goes to a black screen.