I'm running Windows XP (SP3)

I had an "automatic update" install itself on Wednesday evening & requiring a "re-start"

So maybe that was the last "official" update

But I won't be panicking about a lack of "official" support

I have a 3rd party anti-virus + standalone spyware

No I'm not paranoid, just careful

The operating system will still "work"

So don't be rushed into changing if you don't "have" to

I had enough trouble with Windows Vista

IMHO (I'm no PC expert) your PC will still work & providing you have "up to date" security software you need not change for the "foreseeable" future