Vista - SQL 2005 installation disaster

Which I think it 100% my fault.

I tried to install SQL 2005 64bit with the default UAC security setting on.
This gave me only the basic of SQL Services such as books online etc.

I then tried to install SP1 and that is when I understood I needed to have
real full “real� admin rights to install this stuff. So I did just that,
turned off the default security settings, did a reboot and installed SP1.
Trouble is its required to “have SQL 2005 installed� before installing the
SP1 and I guess because the core services such as the database itself is not
properly installed it means I have violated that rule.
SQL 2005 will still not fully install and I am somewhat surprised it even
tried given I patched before installing some core services.
My trouble is I don’t feel condfient I that I know specifically which
“programs� to uninstall and least of all how to uninstall the SQL 2005 SP1.
Basically I think I need to role everything back before I installed SQL 2005
and try the whole process over again with the default security settings off.

Help!!!!!!!!!!