Well,
Many things could have been damaged from the fall. Mechanical drives a susceptible to hits.
So you can't access your drive right? In case you can, you need to take the data stored on it off as soon as possible.
In case you can't, you can try the Ubuntu Live CD approach. Just boot up Ubuntu from a CD of a flash drive -> try to access the drive -> recover data in possible(just transfer it from your OS drive to another flash drive or another drive attached) -> switch back to windows.
If this doesn't work, I guess you may need to take the laptop to a repair shop. In case the drive is physically damaged, you may need to contact a data recovery company as well.
D_Know_WD