XP will not open

Hi,
Windows will not open the desktop! I just see a completely black screen with a cursor.
Preceding this issue I?ve had a number of problems - Windows sometimes refusing to close, iTunes not synching, restore points not being accepted (although on these occasions the PC has rebooted each time to show the "no changes have been made" screen).
The system restore system seems to have been the trigger that?s caused this, the most major problem, where I cannot get to my desktop. I tried to restore to the earliest restore point (sometime in August) shown as being available, but after the PC started, instead of the (for me)usual "no changes have been made" screen, a message appeared that Windows did not start properly, a new hardware or software change may be the cause (there have been none recently) and gives options (keyboard arrow key selectable) for safe modes or last known good configuration or normal start. The screen has a 30 second countdown. Whatever option is chosen, the Win XP slash screen then appears as normal, but instead of this being followed by the usual ?wait while Windows loads your personal settings and the appearance of the desktop, I get a black screen with a cursor (and with ?safe Mode? in each corner if one of the safe mode options was chosen. The same thing happens if I use F8. If safe mode is chosen a page full of what I think are drivers are loaded with a message ?press escape to stop loading SPTD.sys? before the black screen appears.
I want to reformat this PC. It?s 3 years old and due for a complete clean out. But I?ve some recent data not yet backed up that I?d like to retrieve, nothing vital except for hours of iTunes library stuff. The thought of shoving in all those CDs again brings tears to the eyes.
Is there any way of getting Windows to open again ? rescue discs, restore apps, a jemmy whatever??
I?m assuming this is a software and not a hardware issue? I?ve swapped monitors from basic Acer to top end Dell which displays an ?auto adjustment in progress? message during the boot up but with otherwise no difference.
For what it?s worth it?s a Pentium P4 3.2, I gb Kingston Ram, Nvidia 6600gt graphics card 2x hitachi 160 drives in Raid0 running win XP pro SP2.
Can anyone tell me if this problem is solvable and if so how?
Regards,
Ray