Recently bought a new laptop with an extended warranty. Wondering if when a laptop needs to be sent in to the manufacturer for a repair (specifically a hardware repair), is it ok to remove the hard drive when sending it in? I don't want to risk my data (security) while in transit and out of my hands. Nor do I want to delete sensitive files and restore them when my laptop is restored. I guess this would make it tougher to troubleshoot issues and repair the laptop. I don't know what else I could do.
Opening the laptop and removing hardware will void the warranty in most cases. Big PC sellers state this in their terms.
The repair people need to test your system as is, with all the hardware that's included.
Encryption is the best way forward.
See this answer about data protection: https://superuser.com/a/238837/380115
As others mentioned
Without physical security, you can't have strong protection. So I don't know of any very strong, robust security measure for your situation
I guess the following could give you some protection
Change BIOS settings to boot only from the harddisk, so you can't boot from other devices. Make sure to disable network boot, which is usually in the same menu.
Set up a password for changing BIOS settings and for startup, so nobody can get past the BIOS loading screen without resetting the BIOS.
Set up automatic shut down when closing the lid (you should be able to do this in the power saving options). That way, intruders will have to go through the BIOS password prompt to get anywhere.
Encrypt the whole disk. That way, you'll have to get to the PC while unlocked or to add keyboard sniffing to access anything.
You may wish to leave the laptop intact as you could possibly affect Warranty.
Typically, any Return Merchandise Authorization is likely to include a disclaimer about a risk of your data being lost. Unless you specifically request that your data be retained and provide login credentials (which as an option might not be available) your laptop will very likely be completely drive-wiped before the problem is dealt with by the executing service employee.
Most return process scenarios are handled 3rd party and includes a specific drive-wipe/cleansing stage which is adhered to strictly. The default action is to hit your laptop with a drive-wipe utility in the first instance.
Also, because the laptop must be certified as functionally tested before it can be shipped back to you, the end result is that a laptop will returned in a fresh "Out of Box" state.
I would recommend backing up your sensitive data beforehand on the notion that it will be wiped.