Acer Aspire 1360 Will Not see HDD

I have a Acer Aspire 1360 laptop I bought used with no HDD or ram I installed both and for some reason it does not see either the HDD or the optical drive in the Bios and it wont allow me to format it I have made a bootable flash drive with windows XP pro install on it starts up run's set up but only see's the flash drive I also herd that if I booted it without ram that it would give me a error message and did not so I was wondering if someone had some tip's or trouble shooting tip's I can try ? Please!!!!!!