^ If its beta 2 then you dont have to click on show updates, you would by default get a entry in Add/Remove programs showing - IE 7 Beta 2, just uninstall it from there.
It its beta 1 & you dont see it using show updates, then one alternative is to reinstall it & then uninstall it.
OR if you dont have both the uninstall entires - one more thing to do is :
In Explorer/Tools/Folder options/View - check/enable the Show Hidden Folders.
After that try doing the following -
In Start Menu/Run paste the following code & enter
Code:
%windir%\$NtUninstallie7bet2p$\spuninst\spuninst.exe
OR(Check the path in your windows folder)
%windir%\$NtUninstallie7bet2$\spuninst\spuninst.exe