See Resolution: Method 1 (preferable) or Method 2 in
http://support.microsoft.com/kb/923100 (ignore the title).

If no joy, see this related post by my colleague MowGreen:
http://groups.google.com/group/micro...76de7769d04493

How to determine which versions of the .NET Framework are installed and
whether service packs have been applied
http://support.microsoft.com/kb/318785

--
~Robear Dyer (PA Bear)
MS MVP-IE, Mail, Security, Windows Desktop Experience - since 2002
AumHa VSOP & Admin http://aumha.net
DTS-L http://dts-l.net/

RichardOnRails wrote:
> Hi,
>
> Microsoft Update identified four updates as appropriate to the current
> state of my WinXP-Pro./SP2 system. After reviewing them, I selected
> all four and directed that the updates be applied. After the update
> complete, a window opened informing me::
>
> The following updates were not installed
> * Microsoft .NET Framework 2.0: x86 (KB829019)
> * Microsoft .NET Framework 3.0: x86 (KB928416)
>
>
> "Add or Remove Programs" indicates the following Microsoft .NET
> Framework elements are installed:
> * (English)
> * 1.0 Hotfix
> * 1.1
> * 1.1 Hotfix
> * 2.0 Beta 2
> * SDK (English)
>
> Why were the updates not installed?
>
> Thanks in Advance,
> Richard