You mentioned you lugged it around with you. Could be a couple of things due to a severe jar.
Most likely a hard drive issue if it doesn't resolve itself after you've left it on say overnight. Do the following first though.
If the memory stick(s) got a bit loose it would likely blue screen on you but it is something to check because I've seen PCs work until a certain point is reached and then something goes wrong but usually results in a crash but could result in a hang as you describe. With it unplugged and battery removed open the memory compartment usually on the bottom behind a panel that is secured with usually a single screw. Remove the memory and reinstall. Close the panel, turn back on. If it still is having a problem and you have another PC, download yourself a bootable copy of memtest at
www.memtest.org. Run it on the laptop for a few hours. You might find you have some bad memory. If it passes the tests after a few hours your memory is likely fine.
Assuming that's ok, then address the hard drive because we know your memory is good and won't create problems that aren't there on your hard drive or make them worse. Run whatever disk diagnostics you have or do a google search for
bootable disk diagnostics. After running those you should have an idea of what's going on.