My available ram is only half of what is installed
Solution 1:
There is nothing wrong with your system.
You have 8 GB of RAM of which 1 GB is unusable because it is "hardware reserved" (which means that that RAM space is used for embedded graphics and memory buffers needed by various PCI/PCIe devices).
That leaves 7 GB for use by Windows.
That is shown in the left-border under the memory heading as 3.0/7.0: 3 GB used out of 7 GB.
That leaves 4.0 GB "available" and that is exactly as shown.