Help It Took me 9 hours to transfer 6.3 GB file to the WDTV attached WD My Book Studio II 4TB

I don’t know what happened, my friend came to my place yesterday, copied my movies, he installed Linux file system( mine is Windows 7 and his comp is Linux so his portable HD can’t be recognized by windows 7) and updated my Mac Afee Internet security , suddenly transfer rate from my Desktop to my WDTV live attached storage drop, from 30 minutes for 6.3GB file over (WDTV use wireless Belkin N, Desktop is connected through Ethernet cable to the linksys WAG 160N) drop to 9 HOURS for 6.3GB MKV file, what happened? Please help

you might want to attach the source to your pc and perform the copy process in your pc. WDTV doesnt do well with file transfers and management.