Here is the details of my problem:

it gives Windows Failed to start. A recent H/w or S/w change might be the cause.

Launch startup repair (recommended)
start normally

I have to chose Launch startup repair. Then it gives 'sartup repair is checking your system' and then after sometime gives the message 'Do you want to restore your computer using system restore and then i have to choose 'restore' and then new window 'if problem are found, startup repair will fix them automatically' and after several minutes gives the message 'Restart your computer to complete the repair'. when i restart again i get 'windows failed to start....' repair recommended and repair and takes about 20 minutes and gives the message 'start up repair can not repair this computer automatically'

send this info
don't send

then either one will shut down the computer and when i turn on it starts normally and works fine.

adobe update and certain windows update give me this problem. Today i downloaded Vista SP1 and tried to install, it gave me the same problem so could not install SP1.

looking forward to hearing from you all.

Best,
Deependra