My main laptop is down, and I ordered a replacement. To be able to trade I am using a cheap Vostro 3555 from Dell. The problem with the Vostro 3555 is that it had only 2 GB with 1.48 usable, so it was slow. I upgraded to 4 GB of RAM, and it now shows 4 GB (1.48 usable). The usable memory did not increase. This is not a problem on my other studio laptop I had from Dell with Intel processors and 4 GB of memory. I already upgraded the BIOS and chipset drivers for the Vostro. I also upgraded the virtual memory by manually adjusting it, and the computer is now faster but still shows 1.48 usable.