bios reading all rams but only using the first memory card installed

[sa.saru98]

hi, so i have a HP precision 490, and i'm willing to upgrade its cpu, gpu...
i installed rams 2GB, 1GB, 1GB so in total 4GB
but the bios or windows systen use only 2gb which is the first installed card or use a 1 gb if its the first, thought all the 4gb is readed by the bios

i tried upddating the bios, i changed the order of the ram in all ram slots, i have a windows 64bit
i hope there is any thing i can do to fix this issue and thanks for your replies in advance.

 

[cin19]

Your PC can only support the DDR2 Fully Buffered DIMM (FBD) 533MHz ECC memory. So make sure you got the right memory.

 

[sa.saru98]

the dimms are working just fine the problem is that the computer in general just reading he first assembled ram
i think it might be cause of the 3 dimms are from diffrent factories or something like that
but before i do install windows 10 again in he hard disk it used to read 3gb unstead of 2gb