When (Current Version) of Office has min. specs greater than your computer's specs.
When internal modem driver do not want to work on your comptuer as they require a min. of an MMX Processor.
When your ISP's Tech Support says "Sorry, we don't not support computers that old."
Optusnet refuses to support you computer on any of their connections if it's lower than a P-100.
When your ISP's Tech Support says "Sorry, we don't not support computers that old" ; after you managed to get MS Windows 98 running.
Again, OptusNet. True Story.
When you computer's motherboard as VESA extenstion on your ISA slot for your VGA card.
When your hard drive size is still mensioned in Mb.
When the capasity of a CD is bigger that your total hard drive capasity.
When you have SIMM memory modules.
When you have CD Rom drive requires you to insert your CD Rom via a caddy.
When 8 3/4' Inch Floppy Drives.
When you have maxed out your colour depth, and you can still count all the colours (all 16 of them).
When the cost of repairing your computer is greater that what it is to purchase another one with exactly the same specs.
Happens too many times in my job.
When you do not have a PS2 Port for your mouse or keyboard.