I bought the 2012 Walmart Black Friday Compaq CQ58-bf9WM laptop for my daughter and the HP 2000-bf69WM laptop for me. Both are running Windows 8, a 64-bit OS. We just just opened each laptop yesterday for Christmas. The Compaq came with 2 Gig of memory and the HP came with 4 Gig of memory. Both laptops look like they are based on similar if not the same base system. The motherboard only has 1 memory slot. I ordered a 16 Gig (2 x 8G) set of DIMMs; one DIMM for each laptop. I was able to open the bottom of the laptops, take out the 2 or 4 Gig DIMM and insert an 8 Gig DIMM. Upon booting up the machines, they both reported 8 Gig of memory. Success!
Here is the memory that I ordered from Newegg.com: G.SKILL 16GB (2 x 8G) 204-Pin DDR3 SO-DIMM DDR3 1333 (PC3 10600) Laptop Memory Model F3-10600CL9D-16GBSQ