That isn't correct, so there appears to something wrong there, try a reboot, probably needed to update.
Since you mentioned the magic word 'Subscription' check the avastUI, Maintenance, Subscription, if this section exists, check for the presence of Other Options there.
If that doesn't resolve the data displayed in that Registration/Subscription section - Try a repair of avast:
XP - Add Remove programs, select 'avast! Anti-Virus,' click the Change/Remove button and select Repair, click next and follow.
You may need to reboot after the repair.
Out of interest, can you confirm you are using avast 8 (as I'm assuming) and not avast 7 ?