Can I connect a PC hard drive to my laptop with a mere USB to SATA adapter cable and use it as an external hard drive?

You may need an additional power cable it depends on the USB-SATA adapter, especially if it is a 3.5" drive. You may be better getting an external caddy such as this
http://www.ebuyer.com/213422-dynamode-external-housing-for-sata-2-5-hard-drive-usb-hd2-5s You have to get an enclosure to put your drive in that will provide the necessary power that has a sata to usb converter built in. Last time I checked you could get one for under $20 from newegg.com. Yes you can but if it is just for the one drive then an enclosure will be more tidy.
The drive you have is a SATA interface and being in a laptop a 2.5" drive.
If it had been a 3.5" drive you would also need a power adapter which would have been supplied If the hard drive is SATA use the SATA cable to USB but some are indeed ide fortunately most of those hard drive to USB adapters come with SATA and ide socket to go to the USB port and both run on any USB slot. I don't see any reason why not. It seems like it's a plausible usage, but the question is, what are you doing with it, if you are running an old OS, then your BIOS has to allow it, but anything else should be possible

You have to get an enclosure to put your drive in that will provide the necessary power that has a sata to usb converter built in. Last time I checked you could get one for under $20 from newegg.com.

Yes you can but if it is just for the one drive then an enclosure will be more tidy.
The drive you have is a SATA interface and being in a laptop a 2.5" drive.
If it had been a 3.5" drive you would also need a power adapter which would have been supplied

If the hard drive is SATA use the SATA cable to USB but some are indeed ide fortunately most of those hard drive to USB adapters come with SATA and ide socket to go to the USB port and both run on any USB slot.

I don't see any reason why not. It seems like it's a plausible usage, but the question is, what are you doing with it, if you are running an old OS, then your BIOS has to allow it, but anything else should be possible