Brief BSOD on Startup, Startup Recovery Hangs

I have Win 7 Home and in the last couple of days I have been trying to do a backup onto an external drive. The problem comes in when I attempt to start my laptop so that I can begin the backup process, the screen flickers a BSOD, says startup failed and do I want to run Startup Recovery. If I say no, it continues to attempt a restart (each time going thru the same steps) until I say yes to Startup Recovery when it goes through all the motions but always fails to repair the startup. I discovered that if I hit Cancel at the end, it gives me the chance to use System Restore which works in that I do get into my laptop, but doesn't in that the whole startup routine happens all over again the next go round and the only way I get in is via System Restore. I am going to post this next part here on the off chance that the problems are related. The backup onto an external drive has been failing because Windows didn't assign it a drive letter. I have done the following to try and correct that: 1. I uninstalled and reinstalled all the USB serial bus controllers. There weren't any errors showing before I tried that but it was offered as advice elsewhere to someone else and I figured it wouldn't hurt to try it. 2. I tried using Disk Management to reassign a drive letter manually but it keeps giving me an error saying it cannot do that and I need to refresh the list and try again and or close Disk Management and try again. It continues to fail to reassign a drive letter. I thought maybe Event Viewer would tell me something as to why but there was nothing in the Event Viewer that I could understand as being related to the problem. 3. After trying everything I could research here and elsewhere, I gave up and attempted to reformat the drive, at which time I got the following error: "The following fatal alert was generated: 40. The internal error state is 252". This is an SChannel 36888 error and after much more research (here and elsewhere), I got a lot of noise about possible problems with certain games (none of which I own) and Outlook 2007 (mine is 2010 and I've never had a problem with it), and I am at my wits' ends. FWIW, the external drive is a Seagate. I need to make a backup of my laptop (files and registry) to that external drive so that I can do a reinstall of Windows but I not only cannot get into my laptop without a lot of hassle, I cannot get Windows to even see that drive in Explorer, much less write to it. Does anyone have a recommendation on non-native startup repair programs? The problem escapes me at the moment as to why I don't want to use the native one but I don't. I get that such a prog won't fix the drive problem but it would at least be one less headache if it successfully gets me out of the startup problem. Any other suggestions would be warmly welcomed.