|"I am trying to add a second cdrom.I want to add SATA since it is faster"|
You may want to add another optical drive but as far as I know there's no such thing as a SATA cdrom only drive - it would most likely be a DVD combo burner drive - burns and reads both CDs and DVDs.
Optical drives run much slower than hard drives do.
SATA optical drives are NOT faster than recent IDE optical drives - both are max UDMA 66 - UDMA 4 in Windows - they have a max data transfer rate of 66 mb/sec - you can get models that have identical max read and write ratings, the only difference being they connect via an IDE or SATA interface.
"There are 2 blue SATA plugs on the with my hard drives and I am guessing the cdroms go in the orange plugs."
Are you describing the colors of the connectors on the ends of the data cables, or the colors of the SATA headers on the mboard?
The colors of the connectors on the ends of the data cables are not relevant.
According to this,the specs for the mboard:
Four SATA connectors:
SATA1 = Black
SATA2 = White
SATA3 = Blue
SATA4 = Yellow
The only orange header is for firewire.
According to the HP parts list for HP Pavillion a6120n, with the country set to USA, there are two possible models -
GC670AA and GC670AAR
Both use the same mboard.
If your mboard actually has two blue and two orange SATA headers, either you bought the computer in other than the US or Canada and it has a different mboard, or you have the model number wrong.
Does the mboard have P5LP-LE on it and does it look exactly like the one the picture is of in the specs?
SATA drives don't have master/slave/cable select jumpers.
The cheapest way to by them is oem - merely a drive in an anti-static bag - those don't come with the SATA data cable - if you don't have one you need to buy that separately.
A retail SATA optical drive in a box may have the data cable included.
According to the specs for your model, with the country set to US, you already have:
16X DVD(+/-)R/RW 12X RAM (+/-)R DL LightScribe SATA drive
"Ram: 4 gigs
Two HP 1GB DDR2 SDRAM 533(PC2-5300)
Two Kingston 1GB DDR2 SDRAM 667(PC2-5300) 667Mhz underclocks itself to 533Mhz"
533mhz ram is not PC2-5300 ram - it's PC2-4200 ram
The mboard bios always runs all the ram at the SLOWEST specs of all the ram installed
"Motherboard recognizes 3.5 gigs"
That figure doesn't make sense, at least not for what the mboard bios sees, unless you have one ram module that is not 100% compatible with the mboard and only half of it's capacity is seen, or one ram module is not properly seated in it's slot.
Your specs say:
Video graphics Integrated graphics using Intel GMA 950
Up to 256MB (with 512MB or more PC memory)
Also supports PCI Express x16 graphics cards*
NOTE: *Either integrated graphics or the PCI Express x16 slot are usable at one time; they are not usable concurrently.
If you're using the onboard video, the bios could be subtracting up to 256mb (1/4 of a gb) for the amount of ram that is shared with the video, because that amount can't be used by the operating system or by the user for user data, but the onboard video can't share 512mb of ram.
32 bit XP and 32 bit Vista operating systems have a 4gb virtual memory address space limit, for both the ram and for what is needed for Windows. When you install 4gb of ram, only a little more than or a little less than 3gb, depending on the particular system, is actually available to be used by the operating system. You often find that if you install 3gb rather than 4gb, you actually have more available physical memory available to the operating system listed in System Information that you do if you install 4gb, and the system will run noticably better with 3gb, despite the fact all the ram is running in single channel mode.
Your specs say:
Core 2 Duo E4400 (C) DC 2.0 GHz
800 MHz front side bus
Is that what you have?
The parts list says:
Power Supply [Electronic Parts]
5188-2622 250-watt (max) power supply (Zinfandel), Bestec ATX-250-12V) - 100-120VAC and 200-240VAC input (switch selectable), 50/60Hz
NOTE that BESTEC power supplies have a reputation for malfunctioning more often than average, and when they fail completely they are a lot more likely than average to damage something else, often the mboard.
If you have ANY suspicion the power supply is starting to fail, I recommend you DO NOT use the computer and replace it before it fails completely, to avoid the strong likelyhood of damaging the mboard.
Failing power supplies are common and can cause your symptoms.
Check your PS.
See response 4 in this:
DO NOT replace the power supply with another BESTEC one!
In most cases you can replace it with a standard sized standard ATX power supply.
Standard (PS/2) power supply size - 86mm high, 150mm wide, 140mm deep, or 3 3/8" h x 5 7/8" w x 5 1/2" d , or very close to that, though the depth can be more or less for some PSs.
Don't buy an el-cheapo PS.
See response 3 in this:
Also, the 250 watt capacity is okay with whatever PCI-E video card in a slot that may have come with the system, but it's probably inadequate if you upgrade the video card.
Your power supply must have at least the minumum capacity required to support a system with the graphics card you are using installed, or the max graphics card you might install in the future.
(Onboard video - video built into the mboard - IS NOT A CARD!)
You can go to the video card maker's web site and look up the specs for the model - often under system requirements - the minimum PS wattage, and, more important, the minimum amperage the PS must supply at 12v is stated. If you don't find that, any card with the same video chipset including any letters after the model number has very similar minimum PS requirements.
If you want to cover any possible video card, a minimum 600 ot 650 watt power supply will handle any current high end video card, or even a X2 card (two video chipsets on one card) or two cards in two slots.