ngoy :
The only "good" thing that could have happened is that you shook the drive connector loose. Find out where the drive carrier is (typically need a panel popped out and/or a screw removed, pull out the drive and reseat it, screw back in, and try restarting. If that doesn't work you can try slaving the drive to a desktop using an adapter depending on whether the drive is a sata or ide drive and see if it shows up on the new pc.
But, if after the first reseating you can hear the drive clicking a whole bunch as your system tries to boot, then there is no hope except for a recovery service such as ontrack.
yes, try take the HDD out and re-seat it. had this happen and thats all i needed to do to fix it. if that doesnt work, take the drive out and put it into a desktop just like ngoy said. if it shows on your desktop computer and you are able to read/write data without any problems, then the hdd is fine and the problem is the laptop itself (a new HDD wont fix it). if the HDD doesnt work however you can try 2 things as a last ditch attempt to recover your data.
1: when you place the HDD in your desktop computer (before powering on) turn the HDD on its backside, side, vertically etc. try have the drive everyway possible, it may free any stuck heads and give you time to recover data. make sure the drive is powered off or the disks are not spinning before you move it around. i have a HDD that only works when its lying on its backside lol
2:take the HDD out of the laptop, place it in a ziplock back and squeeze out as much air as possible then seel the bag. place the hdd in the freezer over night and the put it into you laptop or desktop pc. freezing it will cause the heads to shrink or contrct from the cold. this could also dislodge any stuck heads.
tip: if you get the drive to work, make sure you DO NOT copy multiple items. dont copy one file and while thats copying start to copy another file, this can cause it to lock up and fail. you can copy multiple files in one go ok, for example: selecting 100+ files at once and copying them is ok. this only opens one transphere window.