Upgrading a laptop hard drive
Prices for laptop hard drives are falling. And as a result, many people are opting to replace what they already have with something nicer.
When you go shopping, there are a few things you must keep in mind. First of all, get the right size. The vast majority of hard drives are 2.5", though a few use even smaller 1.8" drives.
Helpfully, Newegg has an entire category just for laptop hard drives, and they will allow you to filter by this and other criteria.
You next need to choose your interface. This must match your existing drive. Your choices here are ATA and Serial ATA (SATA). Beyond that, the specifics (whether a drive is ATA-6 vs. ATA-7) are unimportant. If you don't know what you need, it is strongly recommended you find out. If someone has a gun to your head and is making you buy without looking up such information, your best bet is ATA unless the laptop is very new.
Next up is the spindle speed, measured in RPM. Higher is better; in fact, higher is much better. Don't touch 4200 RPM drives, and spring for 7200 RPM if at all possible. 5400 RPM is the middle ground. A drive that spins faster does indeed require more power, but it will spend less time working (which will mitigate the power use difference) and be much more responsive.
Up next is cache. Many drives have 2 MB of cache, some have 8 MB of cache, and by the time you read this it is possible some drives will have yet more. 8 MB is very much recommended. If you're forced to choose between this and spindle speed or storage capacity, give up some cache.
Last, counterintuitively, is the actual capacity of the drive. Despite all appearances, this is usually the most flexible need. The best advice is that, having settled on the above, you should buy what you can afford. 60 GB is currently the smallest I would really recommend with any enthusiasm, but if that's out of your budget then so be it.
So, you've got your nice new, shiny drive in your hands. And you laptop that needs a nice new, shiny drive. The process of executing the swap is easier than you might guess. You'll usually have to remove a screw on the bottom of the laptop, and then the drive should slide out. Remove it from its caddy or adapter (laptop hard drives are standardized; these caddies are not), and replace it with the new drive. Slide the assembly back in, tighten the screw that holds it in place, and hunker down to reinstall your operating system.
It's at this point that having real operating system CDs, not some weak-sauce restore partition, comes in handy.