Windows 7 - Windows 7 only allowing 1 stick of RAM

I was having problems installing Windows 7 64-bit for a couple days. It was crashing and taking ridiculously long. After some research I removed all but 1 stick of RAM and everything went fine. After getting 7 installed I tried putting my remaining RAM in and the system freezes at the starting windows screen. It starts up and runs fine when I have 1 stick of RAM in. I have tested the RAM and it is all in good condition. I was running XP pro earlier this week on the exact same hardware with no issues.

I also tried manually setting my RAM in BIOS to:

Voltage: 1.90v and 1.8v
CL:4
tRCD:4
tRP:4
tRAS:12

Anyone have any ideas?

You might want to check for a mam memory setting in bios

bad ram? How many slots are available? Are the sticks of ram all the same?

Are both sticks the same Brand & Speed ? Any overclocking of CPU or Ram ?

Welcome to SevenForums, mweb
You could try blowing out the ram slots with compressed air. Also make sure you have the ram correctly seated in the slot. Alternate sticks and slots to be sure they are both working. Good luck to you with your problem

in certain scenarios the RAM must be installed in pairs.

ran memtest86+ both sticks of RAM didn't find any errors.

yes the RAM are both identical sticks of RAM, the specs are in my profile.

I have 4 slots available and have them in the correct matching DIMM slots. I have tried them in the other set of DIMM slots too with the same result.

check your motherboard. Some motherboards require a certain setup of the ram. 1 & 3 slot, 2 & 4, 1 & 2 or 3 & 4... if you see where i'm going with this. Memtest won't always find a leak... I would suggest test each stick in a "working" slot. If they both work fine "separately", odds are it's a slot match up issue. Asus is notorious for this

RAM specs are in my profile and yes it is a kit where both sticks are the exact same.

No I am not doing any overclocking.

What is the Brand & Model of your MB ?