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I installed 4 GB (2x 2GB) of ram but my laptop doesn't load into Windows and only gives me a blinking _ that won't go away.

After some trial and error I figured out that the computer won't load Windows if one of the new sticks is in the bottom/back memory slot. I tried booting with one new stick in the bottom and it wouldn't, and with just one old stick in the bottom and it would. Both new sticks work at the top slot.

So right now I'm using an old stick in the bottom and a new one at top which is giving me 3 GB (2.37 usable) Which is also a little odd because I'm fairly certain that I had a full 2 GB usable before I started playing with the RAM.

Is there anything I can do it get Windows to boot with both 2 GB sticks plugged in?

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Can you specify what your laptop is and what the RAM is? – Shinrai Jul 8 '11 at 18:20
Just an FYI, I know you didn't state this in your question, but incase anyone else is wondering - no, using a 32-bit operating system with 4+ Gb of memory will not cause this issue. – cp2141 Jul 8 '11 at 18:43
the specs and models are crucial. It sounds like a compatibility problem. – horatio Jul 8 '11 at 19:09

At first glance, I would assume you have a bad stick of RAM. Run Memtest86+ and determine if you have a faulty RAM module. Test one module at a time, or if you'd like, test both new modules at the same time.

While it is highly unlikely (I personally have only seen this happen once in my entire life), it is possible that the northbridge on your laptop is defective. Your laptop could work with only 1 Gb due to interconnect issues on a higher-order line on the address bus (which would only be used with 2 Gb of memory). That being said, compared to the occurrence of RAM faults, I would point my sights towards the RAM first. Test all modules and report back.

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+1 Definitely sounds like a hardware problem. – surfasb Jul 9 '11 at 7:33

It sounds very much like you have a problem with the memory hardware itself.

Use Memtest86 to confirm that one of your memory sticks has failed. Hopefully it's not actually a problem within your memory controller or memory interconnect hardware (I've never actually heard of that being a problem, by the way).

From what you're describing, I really doubt it's not a memory failure.

In other words, when asking "Is there anything I can do it get Windows to boot with both 2 GB sticks plugged in?" - my money is on the answer "yes, you get physically healthy memory".

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