Hi there.I just installed Windows 7 64-bit Professional. I accidentally installed the 'N' version, but I don't think that matters. Anyway, I have 2 - 2 GB simms in my HP dv9023us laptop and when I look at properties for My Computer, it shows I have 3GB of RAM. I shutdown and removed one simm and rebotted and it showed 2 GB RAM, then I put the simm back in and it showed 3GB still. Even on XP 32-bit (sorry, skipped Vista), I was getting approx. 3.5GB RAM. Any ideas what is going on here?Thanks, Mike

Thanks for looking that up. Weird I was getting 3.5 or so on XP Pro 32-bit, but only 3.0 on Windows 7 64-bit.Mike

Orignial answer is deleted by replier. The motherboard on HP dv9023us do not support more than 2GB so it is general if it cannot recognize the whole 4GB memory.See this link provided by derosnec orignially.