Do all PCs have a PCIE slot? If they don't, can we upgrade our RAM

Looks like most recent ATX motherboards have a dramatically reduced number of PCIe slots

PC motherboards This video explains everything you need to know about PCIe slots

pci e x16 slot The PCI Express slot on your motherboard allows you to connect video cards using the PCIe bus standard Most motherboard models also feature an integrated

pc slot PCIe card into the PCIe slot on the board Types of Slots and Cards There are 5 common types of PCIe slots and cards: x1, x2, x4, x8 and x16