installation failure

Hope i am in the right group.
Using Vista Home Premium OEM new, three months old.
Installed SP1, installer showed three phases complete 100%.
Then a notice appeared saying Service Pack not installed reverting.
No explanation.
There were seven entries in my Problem file relating to the installation.
Four of them look the same problem
Problemwcp
File--base\wcp\cmiadapter\installer.cpp

problem--windowsWCPAIF componentx86-microsoft-security-centre-core-xxxxx

problem wcpA

Problem cbs package servicing failure package SP1 KB936330

This is probably very ambiguous but i was hoping someone might find a
clue in it to direct me to correct the problems. I have installed five
items since installation a printer a scanner a virus checker a firewall
and a spyware terminator....have had no previous failures