Hi. I own a Sony vaio PCG-K45F. I know it's a bit old but I still use it to check mail and occasional work. This is my situation. The laptop came with 2 modules of 256MB 333MHz installed RAM I bought new memory to increase the total size up to 1GB which is the limit for that model. The modules I bought are 2 Corsair 512MB 400MHz DDR. The thing is that when I install the modules the computer only sees 448MB (512MB - 64MB for graphics) of total memory though speccy tells me I have 1GB installed RAM. I thought the problem was because of the frequency difference so I made some research on the internet and found that I could fix this with a BIOS upgrade so I tried to do it but the BIOS version I have is the latest and the problem isn't fixed. I want to know if I (or someone like you) could change the BIOS to allow overclocking or some thing that allows my computer to the the 1GB. Thanks PS: I can't post any links to the laptop's support page because I'm new in this forum but if you google the model it normally appears as the first or second link.