I bought a biggest hdd with 500 gb size and after I installed the windows (by the way is Windows 10 64 bit for sure ) I discover that I have only 3.96 gb ram free to use from 8 gb ram (I have two slots with 4 gb ).After that I search on internet how to fix this problem and I find some solution , first wast to enter in run msconfing and to uncheck maximum memory which was already unchecked...Then I saw that my bios run in first version and I upgrade ii , I saw on youtube that I could fix this by searching in bios memory remap and I didn't find this option (my motherboard is an asrock pro 3 r2.0 and is really easy to work in bios but I don't have many option for ram there).After 24 hours full of searching how to fix my problem I decide to write here , maybe you can help me fixing my problem...