Using a HD on two different laptops

I recently ran into quite a predicament.
My old laptop's hard drive stopped working.

So I bought a new one very quickly, so that I wouldn't get behind on my work.
However, I bought too quickly, without looking, and to my horror, I had an AMD C-50 processor, with 1ghz processing speed.
I had unknowingly downgraded the processor by over 50%.
And there were no returns accepted.

I transferred over my 6gb of ram to my new notebook, and hope that it would improve the performance. (yes, I know it's a weird number, and I should really be using twin ram cards, but this is all I have at the moment)

Unfortunately, it didn't.
The C-50 processor is the biggest performance bottleneck in the machine.

Now, I decided, this machine is junk anyway, why not overclock it?
But there were no BIOS options for changing speeds, and nobody on the web knew a practical way to overclock the C-50 either (it has integrated graphics).

This laptop does have its virtues though-- the weak processor means it has a 5 hour battery, so on most days I can take it to work and come back without having to bring my power cord.
But the 1ghz processor isn't nearly enough to do anything intensive in a reasonable amount of time.

-----------------------------
Now here are my questions:
Is it safe for me to move my HD back and forth between my new and old machines? (the old one still works fine, with the exception of the previous dead HD)

Is there any better way for me to move the HD between the two laptops, without having to unscrew the bottom every time?
It isn't practical for me to have to do that every day.

I bought a SATA-to-USB cord, assuming that I could use this to connect the HD to the laptops more quickly, but it didn't work. Instead of booting up, like I expected, the disk whirred, then started clicking (clicks of death?) which scared me, so I immediately powered off and removed it.

I also tried using that cord to connect an old SD to my laptop, to see if I could read the files on the old HD with my new laptop, but it didn't show up in Device Manager, or in My Computer, and it also made clicking noises.
Am I doing something wrong here? Is it actually possible to use a HD with the USB socket? Is the cord intended for some different purposes?

Is there any way for me to replace the AMD C-50 processor with a different one?
It isn't hard to find a cheap 2.2ghz processor on ebay, and even a cheap one would be more powerful than what I have right now.

Sorry, I guess I wasn't very clear with my description of the problem.
---------------------------------------------------------------
My old laptop had a 2.2ghz processor, but the HD no longer works. I took it out, and the rest of the machine is in perfect condition.

My new laptop has a 1.0ghz processor-- the huge bottleneck. And I've already updated everything I could find updates for, and all drivers have been installed.

A hard drive can be used on multiple machines, so I wanted to plug it into the old laptop, which has more processing power, when I need to do things that are processor-intensive, like photoshop or games.
On the other hand, the newer one doesn't use as much power as the old one. That's great for bringing to work-- when I don't need it to do anything intense, but would really love to have the extra THREE! hours of battery power.

I don't want to be unscrewing and re-connecting the HD every day, just so I can use both though. Is there some better way?

And thank you so much for actually coming and looking at this post o_o

Hard drives can be used on multiple machines, but a single Windows license typically cannot (without violating Microsoft's EULA). You may be in a gray area since you aren't using the license simultaneously on 2 laptops. Noel would know.

Leaving licensing issues aside, I'd still guess it would be problematic over the long haul, considering the different hardware, Windows Updates, etc.

If I actually wanted to use both laptops, I would think in terms of 2 hard drives and 2 Windows licenses.

The license is being used on one machine, just with different hardware.
You don't get in trouble for upgrading a CPU or adding RAM right?

Also, I'm fine with spending another gig or so of memory on another set of drivers, and I don't think it would be all that problematic

The problem with two licenses and two hard drives is that I can't afford another license, and I can't afford another hard drive. And also, it would be impossible to synchronize the files on both of them.

Kagamiseki said:

The license is being used on one machine, just with different hardware.
You don't get in trouble for upgrading a CPU or adding RAM right?

You are correct about CPU and RAM. Motherboards are different.

An OEM Windows license is tied to ONE motherboard. If you change motherboards, you need a new license.

A retail Windows license can be used on multiple machines, but ONLY ONE machine at a time.

I don't know if you have an OEM license or retail license.

Noel knows the fine points of Windows licensing.

I don't know how to quote multiple people (the Multi-Quote button doesn't work for some reason). So I'll support equality by not quoting anybody.

DocBrown:
Is this really an issue? My sister once had me test her HD with my laptop to make sure it wasn't shot. When I plugged it in and started up, it simply installed drivers, then worked like normal. And when I put it back into her laptop, I noticed it didn't do any driver installation whatsoever. It just worked, as I assume, with two sets of drivers.

Ignatzatsonic:
Correct me if I'm wrong, but aren't there processors/graphics cards that require different motherboards?
If you're right about saying the windows license is tied to a motherboard-- then does that would mean you'd have to buy a new license if you wanted to change the motherboard. I know many people who tweak and optomize their machines end up buying higher-end processors and graphics cards require a motherboard swap-- but I've never heard anybody complain that they needed to get a new license.

Zepher:
I agree that having two partitions would be ideal, but that isn't practical with a cheap hard drive-- there's not enough memory to go around both partitions if you use them both equally, like I would.
Also, am I wrong in assuming I'd need another license to make a second partition, because that would count as a second "system"?
And I would have just bought a new HD, if I had the time. However, this was a totally unexpected failure, and I needed a working computer the next day. There is no place near me where I can get a hard drive, by itself, and mail would not arrive by morning. Or else the $250 could have been much better spent on a nicer new hard drive.