SysChat - Ntio404.sys

hi there hope u can help, im using vista on an acer5315 lappy and about a week ago it intermittently shut down every day or so
Just a quick flash of BSOD and straight to reboot until the other day it wouldnt boot in normal mode(just a black screen with cursor) so I booted in safe mode,and am in safe mode all the time now
So i eventually got sick of this and investigated, deleted a few progs(more or less unused ones)and updated and ran my antivurus(avast home) and it got stuck-like just stalled-in sys32

I suspected either a virus or a corupted reg or something(im no expert)

i ran a couple of anti spywares
and they seemed to get stuck in same spot

the particular file was the NTIO404.SYS one

heres alist of sys 32

Volume in drive C is ACER
Volume Serial Number is D84B-8B3B

Directory of C:\Windows\system32

11/02/2006 08:09 AM 9,029 ANSI.SYS
01/19/2008 08:42 AM 247,352 clfs.sys
11/02/2006 08:09 AM 27,097 country.sys
04/03/1996 08:33 PM 5,248 giveio.sys
11/02/2006 08:09 AM 4,768 HIMEM.SYS
11/02/2006 08:09 AM 42,809 KEY01.SYS
11/02/2006 08:09 AM 42,537 KEYBOARD.SYS
11/02/2006 08:09 AM 27,866 NTDOS.SYS
11/02/2006 08:09 AM 29,146 NTDOS404.SYS
11/02/2006 08:09 AM 29,370 NTDOS411.SYS
11/02/2006 08:09 AM 29,274 NTDOS412.SYS
11/02/2006 08:09 AM 29,146 NTDOS804.SYS
11/02/2006 08:09 AM 33,952 NTIO.SYS
11/02/2006 08:09 AM 34,672 NTIO404.SYS
11/02/2006 08:09 AM 35,776 NTIO411.SYS
11/02/2006 08:09 AM 35,536 NTIO412.SYS
11/02/2006 08:09 AM 34,672 NTIO804.SYS
09/24/2006 02:28 PM 5,248 speedfan.sys
02/09/2009 04:10 AM 2,033,152 win32k.sys
02/15/2009 09:03 PM 1,152 windrv.sys
20 File(s) 2,737,802 bytes

Directory of C:\Users\\Desktop

ill give any more info that u want but i thought this might help
Im sick to death of it at this stage and Im thinking strongly of re installing vista (or 7)

Anyway it would be great if you could help

Ta
jesijoe