failure of update of sp2

Wndows update attempts failed for the last 1 week
Could you find ways to start the Background intelligence Transfer service
and other items mentioned in the service (Local)which could not be activated
by clean boot etc in the service.Now there is no problem in browsing except
update and streaming news videos of Yahoo and MSN websites which are not
working in spite of existing wmp and quicktime and which are working fine
otherwise for internet browsing using broadband of Tataindicom and is
smooth browsing
No anti virus in my computer now using SP2.All problem softwares dismantled
for troubleshooting for failed attempts for updating of windows software
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K.Sellamuthu