If you're using the default directory, delete all the stuff in your /users//appdata/roaming/bitcoin folder make a new bitcoin.conf file. After blockchain is done downloading, change maxconnections, also change listen to 1 (if you want), and maybe you need to change keypool to make a majority of addresses you probably wont need to have your wallet bloating
This doesn't make sense. Why would you delete the local blockchain, then download exactly the same thing?