Checksum error started it all

[Jim]

This morning my computer wouldn't start because of a "STOP:
C0000221 (BAD IMAGE CHECKSUM). The header checksum does
not match the computed checksum. The image crypt32.dll is
possibly corrupt." I managed to extract a new crypt32.dll
file from the windows xp intall disk, which allowed me to
get into windows again. But now, my taskbar fails to work
at all, some desktop icons don't work (mostly windows based
operations like Internet Explorer, My Computer, Windows
Explorer). Also, I cannot shut down via the taskbar;
instead, I have to go to task manager and shut down from
there. (When I try to shut down, I think it notes that
explorer.exe is still running). What can I do? Please help.

 

[Mistahell]

It is strange my computer wont bootup after reciving a
checksum error.
When windows tries to startup, i get numerous errors such
as :"SYSFAT IS DAMAGED OR CORRUPT" etc and it tells me to
restart
i havent installed or changed anything on my computer in
months so i dont understand why this has happened suddenly.
Someone plz help because i dont want to send my comp to
get fixed if its something simple.

Thanx