if i use a memory stick how can i upload the video to my cpu?

CPU = Central Processing Unit - you don't save things there.

The memory stick on your camcorder is for storing stills- the video is recorded to tape. You'll need to capture the video via firewire (iLink) - if your PC hasn't already got one you'll need to install a firewire card. They're cheap, easy to install and readily available. You'll also need a firewire cable.

I had to read your question twice, (cpu )

Get a card reader, they are cheap and very handy to use. You would put the card from your camera in the reader and open the reader as a drive in MyComputer, then also open MyDocuments/MyPictures and drag and drop your photos into the file.

You can't upload anything to your CPU but you can transfer it to a hard drive. You will need a memory stick reader.