hi,
1.When downloading+installing windows updates,do the new updates replace the old updates automatically? if they don't, they'll eventually fill up the disk space?or do i need to delete them manually

2. How do i post reply in this forum? every time i click reply, they always ask me to enter username and password even though i'm logged in, and when i do so, it says "no particular thread specified' or something like that. Please help