|"My PC is a HP pavilion 533w"|
You have already provided that except for Pavilion.
"Product: Hewlett-packard / P9859a-aba 533w"
P9859a is the specific Product number of your 533w series model.
Parts for HP Pavilion 533w - P9859a
DK282-69001 - 80GB IDE hard drive - 5400 RPM
If it's still the original drive, it's probably a Maxtor hard drive:
The Seagate SeaTools program can test any brand of hard drive, but it can only attempt to repair Seagate and Maxtor brand drives (attempting to repair the problem, under 100 bad sectors, if found, wipes out all the data on the drive). Seagate bought Maxtor some years back and they provide support for Maxtor drives on their web site.
( The SeaTools long test will quit testing when more than 99 bad sectors are found, because then it's certain your hard drive is dying.)
Apparently your model came with a floppy drive. If it still works, you can use the bootable floppy version of SeaTools.
To confirm which hard drive model (s) you have
(the hard drive manufacturer's model number is probably not the same as the HP part number in any case) ....
If you can get into Windows, look in Device Manager.
E.g. RIGHT click on My Computer - Properties - Hardware - Device Manager.
Open up the Disk drives folder - the model, sometimes the make too, is there.
Tell us the model number, and it's brand if that's stated, or you, or we, can search on the web using the model number if the brand is not stated to determine the drive manufacturer.
If you can't get into Windows, you will need to find the make and model on the label on the drive itself.
Answer the questions I ask in this PLEASE !
"MY PC, had ran out of RAM. I think it started storing all excess voletile memory on my C-drive."
You can't run out of physical ram that you've installed in the mboard !
You CAN run out of virtual memory (that's what "not enough memory" messages are about; they're NOT about the amount of physical ram you have)
- if you don't let Windows do the default thing and handle the swap file settings itself, in the Virtual memory settings, if you have not specified a big enough swap file size
or - if you have filled the C partition too full so that there is not enough free space on the C partition, there may not enough free space for the size of swap file Windows wants to use sometimes, or constantly.
Either situation will result in your hard drive having to be accessed more often than otherwise is normal - the hard drive activity led will blink more often in that case, and it will probably take longer for Windows to load, and Windows will run much slower than it should.
How much free space do you have left on the C partition ?
(RIGHT click on the C (logical) drive in My Computer - select Properties - what's the total size of C, and how much free space is there ?? )
"I recently added a stick of 512 MB Ram in the secondary slot behind the original 256 MB Ram."
Apparently your mboard has onboard (built into the mboard's main chipset) video that uses up to 64mb of that (adjustable in the bios Setup), your mboard has no AGP slot, and if you aren't using a PCI video card, that ram amount the onboard video is using is definitely subtracted from the amount available to XP's Windows.
XP just barely runs as it should in that situation when you had only the original 256mb installed. Adding the 512mb of ram should have helped a lot, not a little!
The fact that the hard drive led is still blinking a lot with 768mb or ram installed probably indicates you have one of the problems mentioned above - the virtual memory settings are wrong, or the C partition does not have enough free space !.
If you need more hard drive space - you have desktop computer - if you have only one hard drive, buy another hard drive and install It ! Hard drives are cheap these days !
You DO NOT have to install everything that did not come with Windows on C ! When you have another partition (logical drive) to store data on, when you install software, you can change the default installation settings so that the data is stored mostly or all on another partition !
Parts Pavilion 533w - P9859a
0950-4107 200 watt power supply (HV, PFC, Bestec ATX-1956F) - 100-127VAC and 200-240VAC input (switch selectable)
If that's what you still have, NOTE that BESTEC brand power supplies are well known to be more likely to malfunction than other brands, and when they fail completely, they're more likely to damage something else !
They're the most frequent reason for emachines desktop computers failng to boot !
Failing power supplies are common and can cause your symptoms.
Check your PS.
See response 4 in this:
If it is failing, you can usually replace it with any decent standard sized standard ATX PS with the same capacity or greater.
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:
PC board (motherboard)
DA203-69002 - Echo, GLA
DF215-69002 - Echo, GL
This probably applies to your mboard:
Manufacturer's name: P4G533
HP/Compaq name: Echo
HP Pavilion 533w support
HP Pavilion 533w System Specs
The Quick Start Guide probably has the most info, that's closest thing to a full version Owner's or User's manual they have
See page 103 in the pdf for info about
Using Application Recovery and System Recovery, if you need to. Your original hard drive software installation has a Recovery partition.
The main chipset on the mboard can support recognizing PC1600 or PC2100 modules. Installing faster ram will result in the ram running at a max of PC2100 specs, if all the modules support PC2100 or higher specs.
The PCxxxx spec itself is backwards compatible, but that's not the only thing that determines whether the ram is compatible with using it in your mboard.
Some web sites list faster ram that is compatible for other reasons, but it can't run any faster than PC2100 specs on your mboard.
The HP info regarding the maximum ram module size you can install in each of your two ram slots on the mboard is apparently incorrect.
It can support up to 1gb modules in each slot.
266mhz modules only, 512mb or 1gb (1,024mb)
128mb to 1gb modules, generic, PC2100 listed, only
You do NOT have an AGP slot for an AGP video card.
Installing a PCI video card in a PCI slot usually does NOT disable the onboard video, but you would get better video performance from Windows and the monitor if you connected your monitor to the PCI video card, if the card has more than 64mb of video ram on it.