If the only concern is access to your files, then why not just quickly go out and buy a USB flash drive?  I just bought a very small and reasonably fast SanDisk 32GB Cruzer Flair drive for $10, and I have an ultra-fast SanDisk Extreme Pro 256GB drive that I got for $120, although you can find that amount of storage for half the price if you don't need as much performance.

bugperson,

It is best to leave the current hard drive installed in the computer. The reason is when they replace the lcd cracked plastic they will verify that it is connected correctly and without errors when booting up. They have to remove the lcd to repair.

And frankly, saying that you won't otherwise have access to your files while your laptop is in for repair suggests you're currently not even backing up your data, which is probably something you should change anyway. If your data is important enough that you want access to it while your laptop is in for repairs, it should be important enough that you back it up in case something happens to your system unexpectedly.

Maybe one doesn't want to send a harddrive/ssd which still contains data, account information, browser history, etc. around to be handled by strangers?

Setting up disk encryption might mitigate those concerns, but I would still be uncomfortable. Of course one could clone the disk and then erase.. but removing it would be my method of choice.

The technicians will have hardware to test. If not, even an OS on an USB stick would suffice. If they don't have that, there is something else wrong entirely.

Personally, if there's any concerns I would transfer all your data over to a USB HDD so you have access, then I would use some disc imaging s/w such as Macrium Reflect, then perform a factory reset to put everything back to factory defaults before sending it in.  That should cover all bases.  You have your data, all personal data is wiped from the laptop and simple to restore to where it was before you sent it in for repair, while still providing Dell everything they need to properly perform the repair.

@frfrmthat's a completely understandable desire, but it wasn't the reason the OP gave for wanting to remove the drive -- and in any case backing up data is still a good idea.  I've always encrypted my drive with TrueCrypt or BitLocker, so if I ever had to send a laptop in, I would capture an image of my system with Macrium Reflect as suggested above and then send it in as-is.  If Dell needed to boot my system, they would be welcome to wipe it in order to do so, because I'll just restore my image when I get it back.  But I've never had to do that since I always spring for on-site service and longer warranties, so I've never needed service after the warranty ran out.

And actually OP, come to think of it, Dell specifically warns they may wipe your system while it's in for repair, so you should back up your data even if you decide you could live without it while the laptop is in for repair, because you might not get it back otherwise.  Ideally though you should capture an image, since if they wipe your system and you only backed up your data, you'll still be stuck having to reinstall applications and such.  And yes, if you're concerned about privacy, consider encrypting it first.  That's easy if you have a Pro version of Windows since you'll have access to BitLocker.  If not, then VeraCrypt would be a solid alternative if it works for you, but I don't think it supports systems that boot in UEFI mode, which most systems sold over the last few years do. (UPDATE: Turns out newer versions have added UEFI support, but it seems some systems have UEFI firmware oddities that can make it unreliable, so be careful if you go this route.)

No offense taken! :)

I do back up my data, keep recovery drives, etc.; I should have been more specific in my OP about my concerns. What I am actually concerned about is not having access to my data and work inasmuch as this is my only fully-functioning computer, not that I have no backups. What I do have is an old laptop body with a pretty shot HDD, so my plan was to take my current laptop's SSD out before sending the body in for repairs and slot it into my old laptop's body, so that I could continue working without trying to work from backup copies on a very old, slow hard drive. Does that make sense? And if I put my old HDD into my laptop's casing before sending it off, would that avoid the problem of Dell needing to boot up to make sure the repairs are solid?  

edit: accidental double-post 

I don't know how Dell handles a situation where there's no hard drive installed or a hard drive that contains a boot environment inappropriate for the system.  In the latter case, they might wipe the drive and install a base image to do their testing, but in the former case, I suppose they could install a temporary drive to do that, or they might just say, "We couldn't complete certain tests because you removed the hard drive."  It might depend on what you're sending the laptop in for.

However, about your plan to install your hard drive into an old laptop.  If you intend to try to BOOT that old system off of the hard drive you're removing from your current system, that is almost guaranteed not to work.  Windows doesn't handle being switched to significantly different hardware very well, so chances are it will just lock up trying to boot on your old system.  If on the other hand this old laptop has two hard drive bays and you wanted to install this as a SECONDARY disk just to access the data rather than as the boot disk, then that would work fine.

But honestly, based on everything you've said, I stand by my original advice.  Spend a few bucks to get a flash drive of whatever capacity you require and use that to access your data from your old laptop.  If the old laptop isn't currently bootable, then I guess you're sort of stuck.

I have another question. What if I send in my laptop, with a extra hard drive that I installed? There is 2 hard drives in my laptop, but it only came with one.