The date and time is kept by the battery on the motherboard, it's about the size of an American quarter and shinny silver. It should cost about $3.00 US. When you replace it make a mental note of which side the + is facing, this is important.
Reformatting the hdd won't effect any of the components that you've added. But before you do reformat and reinstall the operating system you should back up all of your important files, and if you have applications that you have downloaded and saved the setup for you should add those as well. You should also think about your emails and address book. Once you reformat the hdd everything will be gone. I would suggest backing these up on either CDs, DVDs, flash drives, or an another hdd.
If you have any doubts about having any infections you might want to consider wiping the hdd with an application like Darik'c Boot and Nook
, this will overwrite everything on the hdd. A format will only take care of the Master File Table and leave the rest, this is like an index for the addresses to the files. In order to boot from this application you may need to enter the BIOS and change the boot order so that the CD-ROM is the first device in the boot order.
As for the reformat itself, do you have the installation CD for the operating system? If you do then it will be a matter of placing it in the optical drive and let it do its thing. It will prompt you to partition the hdd, it will show you the total size of the drive, you can have one partition, or two. If you go with two you can make one about 10GB in size for the operating system and use the remainder for the second partition on which you should store all of your files and applications that aren't part of Windows. It will then prompt you to format the partitions, you will want to use NTFS. The disk will prompt you for everything else. There is a good tutorial for making the installation, you can read it here
. And you can always post any questions that you may have back here.
One last thought, in the tutorial it suggest that you update your BIOS, you should only do this if you have a device which will not function with your current BIOS.
Edited by dc3, 31 December 2008 - 06:10 AM.