Will not start

How old is o you know whether the memory chips are still good? Is there any way you can take these chips to a person you know who can test the memory chips, to be certain that they are still good?
Did you by any chance try to upgrade theletters and numeric designatio memory recently and, if so, did you get exactly the sane memory chips as you had in the PC before? Down to the exact same letters and designators on the chips, so that they are all the exact same?
All you need are mis-matched chips and your computer is not going to work. If get around, it may seem a simple thing to get wrong, but if you do get it wrong, you can simply blow it away,

Try this fix...you will need your windows installation disc for the fix.

Windows Start-up Errors
Step one, you need a Windows Installation CD. If you only have a recovery disk set like the ones from HP or Compaq they will not do what you need done. Under normal circumstances however, you can use a Dell disk because the Operating system is on a stand-alone disk. All retail versions are also acceptable as well as upgrade disks. For a rule of thumb, if the disk has the Microsoft hologram it should work.
While the computer is first starting up and you see the manufacturers splash screen, tap F12 (some computers it’s F9, others it may be another key, you may have to watch and see if the computer lists the key strokes for getting to the boot menu. If you still cannot find it, boot into the BIOS settings and change your boot order there. Save your settings and exit, the computer will now seek the cd rom as its boot source first.
Place your Windows disk in the computer and start it up. When you see the test at the top of the page “Press Any Key To Boot From CD” Just hit the space bar to activate. The next screen you will see will most likely be a Windows setup screen, when you see this press the “R” key to get to the recovery console. It will get there, it may take a little time, patience. Once it loads you will be given a choice of Windows installations, there should only be one, if there are more, always pick number one. It may ask for an administrators password, if you have not set this particular password, then just leave it blank and press enter. The next prompt you see is:
C:\Windows>
You need to type the following:
cd \
hit enter. Pay close attention to the spacing between the characters. There is a space between the character “d” and the “\”
You are now at the ROOT of the drive, this is where basic commands can be given and changed. You should now see the following:
C:\>
Now type the following:
CHKDSK /R
Hit the enter key.
The chkdsk /r command also includes the P command and will also look for lost recoverable information in bad sectors.
There are occasions depending on how corrupt the system is, that this process could take several hours, so be patient with it.
Now, after chkdsk has run type the following:
FIXBOOT
Hit the enter key.
It may prompt you with a warning, that’s ok, just continue. When fixboot has finished, type: EXIT hit enter and windows will reboot. When the system reboots, tap the F8 key during this time and you will see the multi-boot menu come up. Scroll to the title “Last Know Good Configuration” and hit the enter key. If you were having some simple drive errors this should have fixed them.