Can't install ArmA

[stegman 3]

Help!  For love of God HELP ME!!

I used to have ArmA on my Vista system, until i needed to uninstall to do some maintenance.

Now I can't put it back on.

The install runs 50% through then an error pops up saying;

<table border="0" align="center" width="95%" cellpadding="0" cellspacing="0"><tr><td>Code Sample </td></tr><tr><td id="CODE">"File Copy Error (CRC does not match)."

C:\ Program Files\Bohemia Interactive\ArmA\AddOns\roads.pbo.bi.bisign

[EDIT]  Fixed it.  There was a whacking great dirty fingure print on the DVD! Rubbed it off and all is well again.  Phew!!

problem solved.