HP Compaq 4000 Pro Small Form Factor PC Bundle HP Compaq 4000 Pro Small Form Factor PC Bundle Our review model HP Compaq 4000 Pro SFF, priced at £422 inc VAT, packed a Pentium Dual-Core E3400 processor running at 1.3GHz, 2GB of installed RAM (upgradable to 8GB), a 500GB hard drive, and a 64-bit version of Windows 7 Home Premium. In our World Be... The HP Compaq 4000 Pro SFF, like many other budget machines, has a plain chassis devoid of fancy features. Still, for the price, it's a solid performer with a reasonable array of port options. And because it's a bare-bones system, you're spared the blo...