Windows 7 crashing problem.

[quan chi]

I have dual boot xp and windows7 but recently windows 7 has started giving some problems.

Now it crashes frequently during the first boot.After the restart it boots well.(XP shows no such problems)
I have no idea whats the problem.can anyone please help.

[Piyush]

pretty weird actually
I heard there was a software to check the integrity of the windows file, but forgot the name
so google it,will help for sure