I was having this trouble when ever i reboot my computer my computer start check disk and i have to wait till its end or i need to press key in start to stop it but some time i miss to press key then what i say shh....
So i made search this problem here what i found and no more i am having this problem take a look.
Check Disk runs on every boot:
Open a command prompt...
Start >> Run >> Type: cmd >> Click OK >>
Type or paste the following line:
chkntfs /d
Hit the Enter key.
Chkntfs displays or modifies the checking of disk at boot time.
The /d switch restores the machine to the default behavior; all drives are
checked at boot time and chkdsk is run on those that are dirty.
Autochk.exe is a version of Chkdsk that runs only before Windows XP
starts. Autochk runs in the following situations:
Autochk runs if you try to run Chkdsk on the boot volume.
Autochk runs if Chkdsk cannot gain exclusive use of the volume.
Autochk runs if the volume is flagged as dirty.
This can happen if the drive's dirty bit is set.
When a drive's dirty bit is set, autochk automatically
checks the volume for errors the next time the computer is restarted.
This will report whether the dirty bit is set:
Start >> Run >> Type: cmd >> Click OK >>
Type or paste the following line:
fsutil dirty query C:
Hit the Enter key.
Volume C: is not dirty
Volume C: is dirty
[[If a volume's dirty bit is set, this indicates that the file system may be
in an inconsistent state. The dirty bit can be set because the volume is
online and has outstanding changes, because changes were made to the volume
and the computer shutdown before the changes were committed to disk, or
because corruption was detected on the volume. If the dirty bit is set when
the computer restarts, chkdsk runs to verify the consistency of the volume.
Every time Windows XP starts, Autochk.exe is called by the Kernel to scan
all volumes to check if the volume dirty bit is set. If the dirty bit is
set, autochk performs an immediate chkdsk /f on that volume. Chkdsk /f
verifies file system integrity and attempts to fix any problems with the
volume.]]
-----
This will also report whether the dirty bit is set:
Start >> Run >> Type: cmd >> Click OK >>
Type or paste the following line:
chkntfs c:
Hit the Enter key.
C: is not dirty.