How to have peace of mind working on a computer?

With so many scams going on Internet and so many virus/spyware/malware floating around, it's hard to feel safe.

Here are a few things you can do to have peace of mind

1. Always work in a low privilege account. This will assure that even if you did something terrible by mistake, only your account will get affected and your system will be safe. This will avoid all kinds of rootkit attacks, keyboard logging, and operating system corruption. I create an "Admin" account and a "user" account for myself. "Admin" account has administrative privilege and I do all administrative work like software installation and tweaking the OS from that account. For my day to day working I use "user" account. If something requires administrative privilege and I am working in "user" account, the UAC will pop for "Admin" password.
2. Keep your operating system and browsers up to date. Automatic update of Windows and automatic update of Firefox both can be irritating. But this little irritation is worth.
   
3. Install an antivirus software. Gone are the days when you need to pay for anti-virus software and the anti-virus software were irritating and resource hungry. Get Microsoft Security Essentials - it is free, light, no hassle easy to use, it is fast and well integrated with Windows.
   

Other tips:

1. For highly critical sensitive things like banking, use a browser that does not allow add-ons like Google Chrome, Internet Explorer in No-Addons mode.

In Windows XP, working in non-admin account was a pain, but with Windows 7, working in non-admin is expected. With Windows 7, there is no reason, all the above process is totally frictionless.