I run a local computer repair shop so I might be able to help you out a bit.
1) Does your DV9000 have a green nvidia sticker on it near the keyboard? If it has that sticker then you can cash in on a class action lawsuit that was just settled and get a new laptop.
http://news.cnet.com/8301-13924_3-20018186-64.html
2) Norton used to be crap but has cleaned up it's act and does as good a job as any "active" anti-virus you can get (that's an opinion). Also if you have Comcast they offer Norton 360 for free, you can download it by logging into your Comcast account. What Norton and all the others miss that is causing everyone problems right now is Scareware. Scareware is a malicious program that poses as an anti virus, locks down your computer, tells you the problem is this huge pile of viruses it's found and then charges you to fix it. If you have payed one of these keep a close eye on your bank accounts.
The best way I know to rid a computer of viruses, malware, scareware, etc, is to first run MalwareBytes, then run Spybot Search and Destroy. This combo fixes 80% of the virus problems that come into my shop, the other 20% your best off reloading the computer.
The best way to run anti virus software on an infected computer is to use safe mode. Safe moade is a mode in windows that only allows the bare essentials to run and whatever you tell it to. By using safe mode you cna run your anti virus program without most viruses trying to block you. to get into safe mode restart the computer and wait for the POOST screen to pass, as soon as the POST screen disappears hit the F8 key repeatedly untill a list of options comes up and then sellect "SAFEMODE WITH NETWORKING" this will run safemode and allow you to get to the internet to download/update antivirus software.
3) Start the computer up fresh with nothing extra running and hit CTRL+SHIFT+ESC to bring up task manager and look at the bottem of that window to see how many processes are running. Windows XP should be under 45. Vista and 7 should be under 75. If you have more processes then you might want to uninstall some programs that you aren't using.
4) also in task manager look under the "performance" tab to see how much memory the computer is using when you start the computer. Next right click on "my computer" on the desktop or in the start menu and go to properties to see how much ram you have installed. If your using more RAM then you have installed your computer will run much slower than it should.
5) If you have more processes running than you think you should you can go START->CONTROL PANEL->ADD REMOVE PROGRAMS(XP)PROGRAMS AND FEATURES(Vista/7) and uninstall any programs that you don't use if you know what they do...if you don't know what a program does then look it up with google to make sure it's not important to the computer.
6)
WARNING MSCONFIG IS NOT A TOY AND YOU CAN SERIOUSLY MESS UP YOUR OS IF YOU DON'T KNOW WHAT YOU ARE DOING!!!!!!!.
With that warning out of the way go to START -> RUN and type in msconfig. go to the startup tab and uncheck any programs that you don't need running when the computer starts up. Things like word, tool bars, various program updaters, media players, google programs, itunes, qtask, adobe,
DO NOT UNCHECK ANYTHING IF YOU DON'T KNOW WHAT IT IS, GOOGLE IT FIRST, IT MIGHT BE IMPORTANT!!! Once you have unchecked everything you want click APPLY then OK then restart the computer.
Hope this helps. These are just some of the basic things you can do and I'll be happy to answer any questions. if I don't get back to this thread feel free to shoot me a PM.