Windows Security Sheild says Anti-Virus / Avast Not Recogised

[GOINGMAD]

I'm currently using windows XP and for the last few days, every time i start the computer i get this nag
pop up window from Windows Security shield / task bar, stating that; Virus Protection is not
found... so hoping someone can shed some light as to how i can remedy this issue?

thanks 

[DavidR]

This is more of an issue with the WSC Windows Security Center.

To confirm this you only have to check that avast is in fact running, tray icon there and rotating when files are scanned ?
The avast icon has no Red X or Yellow Triangle with ! over it ?
The Task Manager shows both avastUI and avastSvc.exe are running ?

Depending on your answers some suggestions can be given.