Here are some quick tips to help keep your PC running smoothly and protect your data and system:

Microsoft Windows Update

Make sure you have turned on Windows security updates (in Windows XP, go to Control Panel/Security Center- set the updates to 'Automatic').

Visit the Microsoft Windows Update website regularly to make absolutely sure you have the latest 'critical updates'. Go to:
www.update.microsoft.com/microsoftupdate/v6/default.aspx?ln=en-us

Microsoft Outlook Backup add-in

This utility enable you to backup your Outlook files quickly and to a specific location. This is a excellent tool and a really important if you use Outlook.
http://www.microsoft.com/downloads/detai(...)

Scan Disk and Disk Defragementer

You can run these applications every so often to speed up your system. Find them on your PC by going to: Start/Programs/Accessories/System Tools.

System Restore

This is a fantastic troubleshooting and 'insurance' tool.

Before you install new software, run the System Restore utility. Available on Windows ME, XP, and Vista, it creates a Restore Point of your system - a 'snapshot in time'.  

If your PC suddenly starts crashing after you installed that great free download from the web - or if a program that was working fine suddenly starts crashing, you can go back in time to the Restore Point that you recently created, or to a Restore Point created automatically by Windows. You can find System Restore in XP by going to: Start/Programs/Accessories/System Tools. In Vista, type 'system restore' into the search box in the Vista Start menu.

Anti-Virus

Always run an anti-virus program and alwasys keep it up-to-date. If the subscription expires, renew it immediately - it's useless if it doesn't have the latest updates. Be careful opening email attachments, even from friends. Many viruses arrive in emails using an infected computer's address book - with your friend's name in the 'From' line. Free anti-virus software is available at http://free.grisoft.com/doc/2/lng/us/tpl/v5

The free version is not the best out there, but it's better than nothing.

If you want the best protection and you are willing to pay, I recommend VIPRE from http://www.sunbeltsoftware.com - $29.95. They have a 15 day trial version available.

I also recommend NOD32 antivirus, particularly if you are running an older system Go to http://www.eset.com/download/index.php to download the free 30 day trial.

Buy a Router or install a software firewall

If you have a high speed (broadband) internet connection, I recommend a router. This acts as a firewall and protects your sytem from hacking attempts and internet 'worms' - the Sasser and Blaster worms can infect an unprotected and unpatched Windows PC in less than a minute simply by being connected to the internet! A router is a 'hardware' firewall. After setup, it rarely needs any configuration and allows you to connect multiple PC's to your internet connection. I recommend the Netgear Rangemax WPN824NA. It is reliable, easy to use and has powerful wireless transmitter.

Alternatively, a software firewall such as the free version from Zone Alarm will offer you protection - but with a downside. It requires configuration and it can be shutdown by a virus. If you want to try Zone Alarm, you can download it at http://www.zonelabs.com/store/(...)_zadown 
If you are running Windows Vista, you have a software firewall already built-in to the operating system.

XP and Vista's Built-in Firewall

You can turn on a very basic firewall in Windows XP that will give you minimal protection, although it doesn't come close to the protection of a Router or Zone Alarm (see above). Go to Control Panel/Network Connections and then 'right click' on your Local Connection. Then left click on 'properties'. Three tabs appear iat the top of a Network Connections dialog box. Left click 'advanced' and check the box below Internet Connection Firewall that says 'Protect my computer and network by limiting or preventing access to this computer from the internet'. Vista's firewall is switched on by default.

Spam

Don't 'unsubscribe' to junk mail. This just confirms that your address is 'live'. Even just opening junk email can send a message back to confirm that you exist, as it's common for code to be hidden in the email's graphics. The other thing you should do is disable HTML (pictures) in your 'preview pane' in Outlook and Outlook Express. Just previewing your emails with HTML enabled can confirm to a spammer that you exist, as well as leaving you open to malware infection as a result of Windows vulnerablilities.

Your PC's Recovery CD's

Always keep the CD's that came with your new PC in a safe place. These contain your operating system (often called a 'Recovery CD') and the software 'drivers' for your PC's hardware. If you don’t have them, check if your PC's manufacturer has put these files on a separate partition on your hard drive, where they can be accessed in the event your operating system needs to be reinstalled.

Back-ups

Back-up your data regularly. These are the files you cannot live without, or would have great difficulty replacing. They could include your digital photos, the novel you are in the midst of writing, your MP3 music collection, your web favorites, or your email address book. There are a number of ways to back-up. The simplest is to burn files to CD or DVD. Alternatively, buy an external hard drive and copy the data over to it regularly and often. If you want to be really safe make 2 backups and keep one off-site. There are numerous web services (such as www.box.net) that enable you to save files to a remote location. Or make CD or DVD backup and give it to a trusted friend or family member living in a different city.

You may think this is going a bit too far, but only you can decide just how irreplaceable your data is.

If you don't know how to back-up, go to http://www.brooklynpcclinic.com/specials.php?view=13

Passwords

Just be aware that if you use a password consisting of a word that exists in the English language (or any other common language for that matter) it can be broken in about 8 seconds using software that runs a 'dictionary attack'. It's much more secure to use a combination of letters and numbers, symbols such as ? or ! and mix upper and lower case letters. A very basic example could be T42&24t (tea for two and two for tea). It just has to be meaningful and easy for you to remember.

Email hoaxes

Any time you receive an email purporting to be a way of making easy-money by simply forwarding it on to your friends, or a warning about a deadly virus, don't waste your time. This is a form of spam, designed to work like a chain-mail letter. Check out this web link first to see the most popular hoaxes doing the rounds at the moment: http://www.symantec.com/avcenter/hoax.html or go
to www.snopes.com