Difficulty trying to do an inplace upgrade

I have been trying to update my operating system on my Dimension 520 for almost a month.  I've been working with Dell support techs who have led me down every path known to man while never answering a single question I have asked during the painful process.  

 

To digress a bit I bought this system in December of 06 and have installed  many applications programs and associated data.   Several times during this period I got a blue screen of death.   Over time the system would lockup for no obvious reason and require a hard start or other times it would go into the standby mode but not come out.   This and other anomolies happened with increasing regularity casuing me eventutally to ask for help from Dell.  It is important to me to stabilize my system and to do so without having to torally reinstall the operating system.   

 

I thought I was a fairly knowledgeable user but many of the procedures that the techs were recommending were beyond my level of understanding.   When I finally tried to do an inplace system reinstall from the CD provided with the system I got to the point where it wanted a iaSTOR.sys file which apparently is an Intel driver.   The techs gave me totally inadequate information as to how to get this driver at least at my level of understanding and NEVER answered any questions whatsoever.   

 

At this point my reinstall is stuck at the 34 minute remaining point where it is installing drivers and asking for directions to get the necessary files.   The files are nowhere to be found on my harddrive or the system CD.   I was given a web an Intel web site but have been unable to figure out how to download those files and get them to my ailing 520.    The latest advice from another support tech is that I should just replace the Hard drive.   I sincerely doubt that is the source of the problem and would certainly destroy my ability to recover my programs and data.  

 

At this point I apparently need some help in working thru the process to download and install the Intel Matrix Drivers.   

 

As a side issue I noticed a great deal of concern and complaints from Dell users when I Googled the iaSTOR.sys problem so I'm not alone with this problem. 

Any advice and step by steip procedures will be appreciated especially if I can ask questions...