You can delete everything form the startup tab , just keep the antivirus.
For two pass encoding, with h246 codecs, it takes a time to encode a big file. In windows 7 it may take a bit more time, coz aero environment uses a portion of ram already. If you apply the basic theme and then encode, it might be a bit faster.
At the same time ... the larger the encoding time, the better the output quality .