Planned obsolescence.   Now is it the computer or me? Well, like most questions it depends. 

Both, when they slow down I buy a new primary, and still use the old one for a while either for myself or pass on to others in the office.

I try to replace it before it dies.  Sometimes I do a couple of Factory resets before the inevitable replacement. Dying always happens at the most inconvenient times.

I'm a Mac guy, and Macs are expensive.  So I do everything I can to keep the old one going... but when it proves impossible to do that (which tends to be about 5 years)... I buy the latest-greatest.

I've hung in there and I've traded in when the old one becomes too cumbersome. I've found it much better to replace in advance and not when it's a screaming emergency.

Depends , I have had them die on me and when the computer frustrates me to a certain limit then I know it is time for a new one.

I hang on to it until I can't get any more out of it.

I just upgraded mine with windows 10 and it's good for another 5 years!!

I tend to hang on to them until I get tired of them or they are no longer functional

I get a new one before the old one dies, move everything over gradually, extract/stash the hard drives (except for one PC from 2001 I needed for an astrology program that I just UG for W10 and it will be gutted & going to the electronics dump soon.)

RIP dolling. 🙏

Generally as long as it is working I keep using it, when the keys stop working I know it is time to change.

If I have a sign of slowing down or an issue that is going to slow me down, I will buy a new one and pass mine to someone else. I don't have time to deal with any issues or slow-downs!

I fall somewhere in the middle. I hang on longer than I should but tend to switch computers before my old one completely dies. I hate switching due to the amount of time it takes and that I am not really a techie, but I always appreciate how nicely and how much faster my new computer is and find myself wondering why I took so long to do it. 

Replace as needed, as necessary.  

When computers slow down I go nuts. No patience for that! Remedies have never worked for me - I have to buy a new one.

Whether I need to or not, It's a new puter every 15 years. 

However, a top-o-the-line, at its time, less than 5 years old should benefit from shaking out the junk. Slow downs occur when things like the online video edit suite starts tagging all hard drive images. Unfortunately, some stuff is so well embedded, abandonment is the easiest solution.

And of course we all know that Chinese made electronics has an embedded surprise we know nothing about at this time. What's a person to do?

I do know if one waits until their prime croaks, it's not going to be a good day.

I used to upgrade more frequently, but the updates aren't as dramatic as they used to be.  I'm not sure how old my current desktop is, but it's doing great. No need for now.  My laptop is a couple years old and just fine.  In fact, I use an iPad 2 for showings that's at least 5 years old. 

When it's time to call it quits I don't hang on until it dies.  Order a new one asap!

I have almost every computer I've ever owned.  Wish I still had my 386, I have a few games that only run on it.

I have had my computer for 6 years - and it is still going. I keep thinking it will go soon, but hanging on as long as possible.

I have two laptops so if one goes I have a backup. When they get to a certain age and start doing funny things, I start pricing replacements and buy a new one.

When the hard drive gets 1/2 full. Better start shopping or up the RAM. 

I'm a Mac user since 2013.  I have always bought the most ram and biggest hard drive plus fastest processor whether buying Mac or PC.  

Yes, Mac is more expensive than PC up front, but they work a ton better and come with most apps most people need included.  PCs don't.

My philosophy is this is a tool, and I like my tools to work well.  Plus it's a deductible business expense.

My 2¢

I think it depends what slowing down means.  Our traveling laptop moves faster than our desktop...A

We update our computers when needed. 

My time frame is 3 years. Then time to change. 

My next is Surface Pro waiting for price to drop. Whatever you have in mind skip Huawei it will steal all data.....

My computer is several years old. Probably time to get a replacement and retire the current one. 

Usually when it slows or memory gets full, but my last one just went dark. 

I try to replace it before it dies, but only shortly before!

Use to hang-on now I make a move

If you mean dies then yes. The trouble with Macs is that they are hard to kill.

If you own a Macbook you probably will have that machine for many years Peter.

New one.

Great answers are here.

If a computer starts acting weird, I go get another.  Cannot be without one for the biz.

Dpends on which happens first

My Desktop is 9 years old and do for a new one.

 Fresh.

Larry hates seeing the dump grow and grow with everything that we throw away. He knows how to work on our Lenovo's and we tend to keep them until we can no longer work with them. 

I build my computers and upgrade components as necessary as I have a monster system that has serviced my needs for over 8 years now

I held on to my old MacBook for about 8 years... took it with me through all of High School as well as all of University. Used it probably 3 or 4 years too long, but it served me well enough. :) Now I have a new MacBook air and hoping it will give me another 5 or so years of life. 

I will try to repair it if it slows down and if unable, get a new one.

Funny you should ask...  the new one arrived yesterday and sits in a box while I continue to deal with this slow one.

No.