how to prevent?

[aljazera]

one of my friend hack my computer, he can creates or delete files as well as he can fully access of my pc. i don't know how can i protect my pc from his access. i think he is using sub7.
help me in this matter please.

[YeOldeStonecat]

Well...I'd start by making sure I'm behind a NAT router.
Make sure the Administrator password is not left blank....
Put on a software firewall..such as Comodo
Run a good antivirus program..such as Kaspersky (they even have a free one called AVS) or NOD32.
Run some good anti-ad/spyware programs such as Antispyware and AVG AS and Spybot Search and Destroy.