Windows 7: System not using all of my memory

I have an HP i5 with 8 gig of memory. Memory is never used more than about 35%. At times the system is really slow. Two Questions:
1. Why isn't all the memory being used?
2. What can I do to speed things up and potentially use all of the memory?



Thanks in advance.

The HP PC, is this a desktop or laptop? How many cores does the CPU have? If mutlicore, are all cores enabled?

1st question, do you have 64-bit Win 7? 32-bit can only access 3.3G or so.

When the system is slow, have you checked Task Manager to see if any processes are hogging the CPU?

In order to use all your memory (in reality, you don't actually want to use all of your memory) you have to run enough programs simultaneously to require that amount of memory. Windows 7 does use a portion of your memory for SuperFetch but that memory is indicated in Task Manager as "Available".

Adding more memory to a machine doesn't magically make it run faster unless you don't have enough physical memory which causes the OS to start swapping to disk. Since you say your system never uses more than 35% of your 8G, I doubt if your memory is the issue.

Answers;

1. Memory use/allocation is determined by the system; if not required, it is not used.
2. You could adjust the page file settings, not recommended, or, to use all the memory, open several memory intense programs which will generally have the adverse effect of slowing the system down.

See the following link for page file information;
http://tweakhound.com/windows7/tweaking/7.html

HTH

For us to help you properly you need to completely fill in ((My System Specs)) completely.
Click on My System Specs lower lift of this post. I will give you a idea what is needed.

System Manufacturer/Model Number HP Pavilion dv6 Notebook
OS Windows 7 Ultimate 64 bit. SP-1
CPU Intel i5 M 460 @ 2.53
Motherboard ASUS P6X58D-E
Memory KINGSTON KHX2000C9, Hyper X,12 GIGS with Corsair cooler
Screen Resolution 1366X768

Keyboard Notebook
Mouse USB
Case Notebook
Hard Drives SATA 500GB Internal
Internet Speed 5.0 mb

note: In post #1 you said 8GB, and your last post says 12GB.

Try testing with a clean startup.
Troubleshoot Application Conflicts by Performing a Clean Startup

Is this when you are online? If so as you sate your internet speed is 5Mb, have you checked the actual speed with a reliable checker like: Speedtest.net - The Global Broadband Speed Test
Test you speed at diffenerent times of the day and report back here!

Something isn't right here. OP says it is a HP laptop, yet the specs he listed has a desktop motherboard,

ASUS - Motherboards- ASUS P6X58D-E

with desktop ram,

Kingston HyperX KHX2000C9 6GB Kit UnReview

Maybe post the full model number of the laptop as dv6 isn't enough to go on.

The mother board and ram are out of my specs, cooler included. Check My System Specs.