Resolved XP Pro takes a long time to load then won't run things

Long post sorry.
Sager laptop w/XP Pro SP3
Takes about 1/2 hour to get to log in screen, black screen with movable cursor for about 15 mins before desktop shows on screen. Waited for over an hour and taskbar never showed up.
Tried to do a repair install. Booted to CD and it said it couldn't find a hard drive.
Tried doing a system restore, normal or safe mode tells me system restore is unable to protect computer, reboot and try again (or at least something along those lines).
Tried running sfc /scannow and get error code 0x000006ba (RPC server unavailable), tried checking services but it never comes up.
Tried creating a new user to see if machine would run better but nothing ever shows up in the window.
Have closed everything in startup that isn't essential, uninstalled everything newly installed as well as anti virus.
Ran AVG from a command line and it scanned the machine as it should and found no problems. Uninstalled it afterwards
Scanned with Spybot, scanned normally, no problems found
Have looked for solutions on various forums with no luck.

Any ideas please

Thanks

 

Hi ataxia162, when you wait the ½ hour, does the laptop work OK or is it slow all the time? Neil.

 

Hi, Thanks for the reply. It is very slow opening anything, takes maybe 10 mins to open my computer. Many of the windows stuff won't even run which is why I tried sfc /scannow because I figured some of the windows files may be corrupt but that won't run either.
I asked the lady about how it was acting leading up to the problem and she said things would take a long time to load and kept getting the message not responding.

 

Try testing the hard disk with the disk manufacturer's utility. There may be bad blocks on it.

 

Thanks to everyone who made suggestions. I determined it was a bad hard drive since the manufacturer diags couldn't do anything and the windows cd couldn't even find a hard drive