You have two choices - either you are simply replacing the tapes with a hard drive or you get a PVR where the box can turn itself on and record the shows you like to watch even when you didn't realise they were on.
For the first alternative most modern tvs now have a USB port where you can simply plug in an external hard drive - they usually mistakenly refer to this as the pvr function but it is not because it requires that you program the shows individually as on the vcr being replaced.
For a proper PVR you need an account with a web service that maintains a complete tv guide where you advise what shows you like to watch. The site then uses the internet connection to the PVR to program in all the shows for you. Some of these sites offer a lifetime free service if you buy the right PVR so you need to check there first before buying if you don't want to have to pay an annual fee.
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