My compaq presario f700 has difficulty booting up.

Windows Start-up Errors
Step one, you need a Windows XP 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. You can order a boot up floppy disk from here: http://support.microsoft.com/kb/310994 with this file, if you know how, you can use “ImageBurn” to burn the file into an ISO file which can be burned to a disk. Now make sure your computer boots to the cd rom first. If you know how to do this skip on down, if you don’t, 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.

Boot your computer into safe mode and defrag your hard drive. when it finishes try booting up normally. if the same problem persist. boot into safe mode again and do a scandisk. when it finishes try booting up normally. If the same problem persist try and recover your important files and essential drivers for your PC, and reformat your hard drive.