Crash after system restore after sp2 update

After install of sp2 had problems getting on internet and other problems with system being slow.  Tried to restore before the point of the sp2 update and computer crashed did not allow me into the system, xp logo  would come on with the bar then would go to a gray screen but would not shut down on its own. Would go through this same cylce unless I manually turned power off.  I called a service tech and he told to reinstall OS with the cd and go through the repair mode.  Went through this and got several errors the last error read: The procedure entry point getlums could not be located in the dynamic link library MSDART.DLL.  It would not allow me to go any further from this point and eventually went into a blue screen and started a physical memory dump.  The dell service tech told me that I would have to reinstall from scratch and loose any info saved on my computer.  I have a dimension 4600 pentium 4  at 3ghz, 120 gb hard drive.  Does anyone have any ideas?