continual boot, reboot loop - success

I'm writing to share a success story. A friend's computer got stuck in the infamous boot, reboot loop after I replaced faulty memory. F8 at bootup followed by turnoff automatic reboot allowed me to start in safe mode and turn off the automatic reboot option in My Computer -> properties -> advanced -> system startup settings. Rebooting the system finally allowed me to see the "stop" error message where I learnt that the file i740dnt had stuck in an endless loop. System restore was singularly unsuccessful. Searching for the file revealed that it was a dll and it was where it ought to have been, but it didn't show its extension. So in "windows explorer, tools, folder options, view ", I had to select 'show all files' and untick the options to hide file extensions and protected files. Now the correct extension was shown. An internet search revealed that i740dnt.dll was part of the Intel740 video driver system. A search on my computer (icluding system & hidden files) for all files with i740 in the name resulted in a number of files including i740nt5.sys.
All of these except the latter were on my friends computer, but there was a file i740nt5 with no extension. Could it have lost its extension? The file size & date were correct, and it was where it should have been. So after taking due precautions, I renamed it to give it a '.sys' extension and rebooted. Voila, hallelujah, yes! - it worked!!
Lessons learnt: 1: MS is very very naughty to have the automatic restart as default if there's a problem. You must see any error messages if you're going to have any chance of fixing them. Bad mark Bill!! 2: One must be able to see file extensions and hidden/system files if one is to successfully undertake some remedial work. 3: System restore is very limited - it's much better to have a ghosted image from which to restore a problematic system. 4: Make backups before undertaking any work of this nature - vitally important.
Finally, only do something like this if you are aware of the risks and have sufficient expertise.

 

I have been going through the reboot X ?? with XPPro and after reading this post I turned off the auto restart. Now it wont fail and I have done a dozen cold starts since.

I suppose that could be considered good news to some folks but I hate it when something like this happens.