Speaking of getting systems that have hard drives that aren't formatted or taken out, when I purchase a computer from a thrift store, I check to see if the OS can boot, and if not, then I can run a live version of Linux, try to access the internal HDD to see what's stored on the drive without the system hooked up to the Internet for security reasons and if there was/is a nasty virus on the hard drive. If there is anything disturbing on the drive, I would zero out the drive three times and get it either destroyed, or install an OS on it with low level formatting to prevent the files from getting restored.
I have an IBM ThinkPad R40 that was used for a business (the battery was hardly used and has 60 cycles out of the maximum, which I believe is 5,000 maximum) and there was no personal or disturbing data on the hard drive whatsoever (thankfully). Other computers I've purchased with or without personal/bad data:
Dell Dimension 4550 <-- was used at a dentist office 24/7 hence 4 bloated caps by the CPU, but still runs
Dell Dimension E510 <-- was a personal computer that ran Windows 7 Ultimate and had some data on it, but I zeroed it out 3 times and installed linux on it
Packard Bell Pack-Mate 28 Plus <-- HDD was upgraded from the 210MB to 428.1MB Seagate HDD and someone's kid(s) used the system back then, hence computer games on the hard drive, and Windows for Workgroups 3.11 was installed on it (zeroed it out twice, but no personal data whatsoever as well) and upgraded the HDD to a 2GB CF card and is now a multimedia system (from IBM PC Speaker to Roland MT-32/GM) for games and stuff
HP Pavilion N3350 (no personal data since the HDD was wiped and booted into MS-DOS <-- system files after formatting with a bootdisk)
HP Pavilion 7955 <-- going to test the system sometime and use it as a sleeper computer and run Windows 98SE on it by purchasing a GeForce3 or equivalent card
I always tell people before you get rid of your computer, always take the hard drive(s) out for security reasons. Also, if someone is about to give you a system for free, tell them to take the hard drive(s) out if there are any. The MFM hard drives were impossible to take the data off (would take months, for example, the Menendez Bros. case of 1989 when they wiped the hard drive to remove/corrupt the will their father saved, which was on an IBM PC XT system) since they were meant for low-level formatting, as well as ESDI and SCSI Hard Drives.
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Systems from the Compaq Portable 1 to Ryzen 9 5950X
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