2 GB Ram is not working

Hi guys I have bought Princeton 2 GB DDR2 800 MHz Dual channel when I installed the ram on my computer DELL OPTIPLEX 745 2 and 4 error lights glow. When I press power button the bios doesn't load with no beep sound when I installed it in DIMM 3. But when I installed it in DIMM 1, 2, or 4 Bios doesn't load and give me the beep sound. But all the fans were running and when I touched the RAM it was also normal warm.

!!!!!!!!!!!!!! Please Help. !!!!!!!!!!!!!!!!!

With all due respect to the shopkeeper, my experience with computer parts is that good and cheap rarely belong in the same sentence.

You need to find out the maximum memory your motherboard will take and what type and speed memory it will take.

Google is your friend

http://www.dell.com/downloads/global...5techspecs.pdf
Maximum RAM accommodated is 8GB unless you have the Ultra Small Form Factor. That chassis limit is 4GB.

The manual
ftp://ftp.dell.com/Manuals/all-produ...uide_en-us.pdf
also says that after you install more RAM, you need to follow these instructions:

The computer detects that the new memory does not match the existing configuration information and generates the following message:
The amount of system memory has changed.
Strike the F1 key to continue, F2 to run the setup utility
9. Press <F2> to enter system setup and check the value for System Memory.
The computer should have changed the value of System Memory to reflect the newly installed memory. Verify the new total. If it is correct, skip to
step 11.
10. If the memory total is incorrect, turn off and disconnect your computer and devices from their electrical outlets. Open the computer cover and check the
installed memory modules to ensure that they are seated properly in their sockets. Then repeat steps 7, 8, and 9.
11. When the System Memory total is correct, press <Esc> to exit system setup.
12. Run the Dell Diagnostics (see Dell Diagnostics) to verify that the memory modules are operating properly.

If you're doing all this, and still have a problem, my first thought is that you've got a malfunctioning motherboard.

It seems that you aren't alone in trying to use 800MHz 2GB RAM sticks and having it fail.
Optiplex 745 supported memory options - Desktop General Hardware Forum - Desktop - Dell Community
http://en.community.dell.com/support.../19072844.aspx

According to the specs, 2GB 800Mhz DIMMs are not supported. You have to use 667Mhz DIMMs or drop to 512 or 1GB DIMMs for 800Mhz.

http://www.dell.com/downloads/global...5techspecs.pdf