Definitely the RAM requirement
The absurd published RAM requirements were the worst thing about Vista (well, one of the worst things). Manufacturers blindly made machines with just 512GB RAM and those machines were actually too slow to be usable.
And it continues today. Windows 10 on machines with 4GB RAM and a spinning rust drive are just not usable for real work by ordinary people. We just took on a new customer with half their machines, despite being only 3 or 4 years old, having a mechanical hard drive! And they are SLOW... 45 minutes to boot sometimes!
Microsoft should just say 'minimum requirements 8GB and an SSD' now.
Biting the hand that feeds IT
