Help-need To Reformat Hard Disk&reinstall Programs

I have recently restarted using my 2 yr old Dell desktop after an 8 month Hiatus. It is running windows XP– I have had trouble (sluggishness and error messages/sudden freezes) for several weeks and after upgrading my Norton anti-virus and running a scan- I found I have W32 blaster worm that Norton "can't remove". NOW- I can't even start the computer. I get as far as a black screen with something like "strike F1- setup or F12 boot menu. " I've played around with changing the some of the lines on F1 and F12 but it isn't helping me get to windows. (obviously I am pretty unknowledgeable about boot menus and the like) checking some gquidance on the microsoft site– it sounds like I might need to Format (or is it reformat) my hard disk and reinstall all my programs. Do I need to reformat? or is ther some other way to get my computer going again. If I have to reformat–How to I do that? (and, is there anyway to save some vacation pictures that are on the computer now?)

""unplug any cable/line from the internet"" I guess you have not got a ""start-up disk"" for windows and I also guess you have not made a ""rescue disk"" for Norton av 1/ First I would try to boot up in safe mode switch on your computer you will need to be quick to press F8 if you have done this quick enough you should be given an option of safe mode and select it if this works run a virus scan straight away 2/ If this doesn't work restart your computer but this time try to open up your Bios by doing the same but this time pressing F2 , then under advance setting or find the option to boot up from the CD drive then save/exit and then put your Norton anti-virus CD in leave it in and reboot see if this gives you an option to scan this way 3/ It sounds however You may need to re-install from scratch, you will have to change your bios to reboot from the floppy disk drive again when you've done this put in your OEM "rescue disk " which should have come with your computer leave it in then reboot and this should load up your internal settings you will also need the disks from you PC maker that contain your drivers. If you don't have rescue disk try PC World or your local computer place Quoting your PC model and operating system, or ask a friend to check out www.answersthatwork.com and see if they have anything under library for you that can be downloaded