How interchangable are laptop hardrives?

before I pry and screw around with this, I hope to get some insight.
I have a toshiba with an internal harddrive that is great. My girlfriend owns some awful dell inspiron (Iguess it isn’t that bad, actually)
I had some incidences with my screen and keyboard on the toshiba and would like to temporarily swap it into the dell. Is this possible? Aside from the obvious physical specifications, what do I need to take into consideration before the swap?
Is the swap just an all-around bad idea… hell, will it even work?!

I’m no expert, but if you swap internal hard drives and then attempt to boot the Dell you’re likely to encounter problems. Among other things, the drivers for the screen, pointing device, keyboard, etc. are unlikely to be fully compatible.

It’s relatively easy to access a hard drive from another PC - just get a USB hard drive enclosure (they are cheap and easy to find). Insert your hard drive and connect to a USB port on the Dell.

I own an external harddrive but have always feared that laptop hard drives would be too small to fit and that scared me away from bothering to look inside and incur more problems.
Are all ports generally universal?

Desktop drives and laptop drives have different size connectors. There also are two types of laptop drives, SATA and PATA. They aren’t interchangable.

If they are the same and you do swap them it is unlikely to work well if at all. I wouldn’t recommend it.

As yoyodyne notes, the external drive enclosure must be compatible with the hard drive. It shouldn’t be too difficult to make that happen.

As others have said, it is generally a waste of time trying to get a windows machine to boot a hard drive that did not come from the same exact type of machine.

External enclosures are cool, but for temporary use like this, I would recommend a combination SATA/IDE to USB 2.0 cable, such as this one. It has the advantage of working with 2.5" (laptop) and 3.5" (desktop) IDE hard drives as well as SATA hard drives.

It will not be the best for regular/daily use, but very handy as it allows you to mount any common type of hard drive, rather than only one type, as is the case with most external enclosures.