<div>
Thanks PUNKY but...what can I do? 
</div>


<div>
If you wanted system recognize all memory, you have to use 64 bits OS. As now, you will have to accept the memory amount recognized by your current XP. This is normal. 
</div>


<div>
I have seen other laptops using Vista they recognize all of the 4 GB, so if I install Vista, will it work?<br />
Thanks.<br />

</div>


<div>
Vista will be same as XP if they are 32 bits OS. I have also seen 4 gig recognized all on some system which has 32 bits but rarely. There is nothing wrong with the memory or your system, it is just limitation of 32 bits OS. <br />
<br />
I believe it would said in your system manual as well. 
</div>


<div>
<div class="content wysiwyg-content">
I just bought a HP Compaq 8510p and an extra 2 GB module for a total of 4 GB, BIOS shows correct count, but WinXP only shows 3 GB<br />
<br />
Why?
</div>
</div>


I just bought a HP Compaq 8510p and an extra 2 GB module for a total of 4 GB, BIOS shows correct count, but WinXP only shows 3 GB

Why?

HP Compaq 8510p wrong memory count

Components are those devices that are internal to a computer -- the PC boards, the central processor (CPU), the memory (RAM), disk and video controllers and so on.