Help me! I cant download express update KB934238 !

i checked for updates and it was 3 for express updt.2 has successful download
and install but the 3rd ( KB 934238 ) cant download.It show me:Prepairing
download...and above download failed !!Where i should check and what? This
update dont download ! Could be a virus hidden process ? Could be from my
network service provider ?
I even lower level of the antivirus and firewall but nothing !
Buy-the-way,always when i scan entire pc with antivirus it found 1 hidden
process in rootkits!(it dont tell me what it is,at the end scanning overall
its o.k.)Could be this ?
THNX & best regrds!