I replaced the motherboard, CPU and Video card on a fully updated Win7 system. It is a dual boot with UBUNTU 11.10. Ubuntu works fine! windows wont boot. Startup repair finds no errors. I am thinking it is the hardware abstraction layer (HAL). I don't want to lose every thing, although I could use UBUNTU to copy files to another disk.
More aboutupgrade motherboard boot failure
If you are getting a bsod, it is because windows does not like when you change your motherboard.
Is your copy of windows OEM or retail?
In general OEM is supposed to be for one board only.
This is not to say a fresh install will not fix it(90% chance it will if you are just getting BSOD's), but my MS rule, OEM is good for one system only and the system is locked to the motherboard.
Originally upgraded from a retail Win XP about a year ago. Boot fails just as the flag starts to show. No BSOD just a reboot. In Startup Repair it runs and finds no errors in the files. Since my original MoBo and processor were 6 years old, I suspect the chip set drivers. I cant get Windows yp enough to load them. I could get them using UBUNTU but I don't know what to do next. Maybe buy another hard drive or install on my second drive whic has a lot of room.
I reinstalled Win7. I had backed up all my6 user accounts. Win 7 also backed them up. Mostly gor every thing up excwpt I can't find my old thunderbird mail.