can not vidoe file in xp

hi i have xp pro
512ddr
instaled nero 6.3
win media player 10
was able to play this files on my pc before(last week)
since then had little crush and had to reinstall nearly everything (learnt to back-up since first hard disk failure:) )
now when i try to access file it says that
can not play the file access is denied.0x8070005
i am logged under administrator.
file us in shared folder and some of them are in the other folder.
this are video files (avi etc)
any suggestion?
my thinking:
maybe no suitable codecs?
maybe need configure this 2 players to play this type of file?
since the crash i installed sp 2
thnks

sry can not open video file in xp

Have you tried to open the file elsewhere? Is it possible it got corrupted when you backed it up?

i have few video files like that and am not able to open any.tried using nero and win media player to open them but without any success

But have you tried opening them on ANOTHER MACHINE?

I do not have a current link, but try "Irfan view", it is a sort of multimedia viewing & management tool. If it cannot open things, it does give you some helpful error messages.

At first sight, I suspect you may not have all the codecs you need?

Cheers