I purchased it frim Amazon script say it was for d600. What does this I mm fo tell u.

1 GB DDR-333 PC2700 Non-ECC Unbuffered 200 pin 2.5v CL=2.5 memory 64 x 8

If the RAM you purchased isn't certified for this model system, start with RAM that is - this is an older system and as a result is pickier about the quality of the memory you install.  In particular, avoid "Value" RAM -- which is generally built to sloppier tolerances.  

Is the system running the latest BIOS?  If not, start there.  If it is and the RAM still won't work, see if one or the other module will work -- if one does and the other doesn't, one of the modules may be faulty. If neither works, it could be bad RAM - or a memory socket or memory controller that's failing (this is an 8-9 year old system, so it's not inconceivable).

Gonna keep at it. Not sure what bios is but will find out

Hi ward wonder,

The Latitude D600 / Inspiron 600M will be offered with a base configuration of 128 MB and supports up to 2048MB. Memory expansion is accomplished through SODIMM modules of 128MB, 256MB, 512MB and 1024MB; up to 2GB total system memory.

In addition to ejn63, you may check the slot by using the old memory. Place the Old working memory in the slot1 and restart the computer, then check the memory to the slot2  and restart the computer. This can isolate the slot on the motherboard. If both the slots are working, the issue might be with the new memory modules.

When you install the new memory on the computer, do you see any of the LED blinking(Nums lock, Caps lock or Scroll Lock)?

Also, refer the following table which has memory configuration:

Awaiting your response!

I contacted the company that I bought the memory from they said it was part of a bad batch and are sending me out another set. Hopefully this will solve the issue.

Thanks for your assistance.

Hi ward wonder,

Glad to know that!

Should you require any further assistance, kindly private message me.

Awaiting your response!