It would surely be a daunting task if you do not seek help of additional software to secure your computer and ensure your safety on the big bad Internet. It is fine if you are against spending more money. But, at the least install some basic tools like Antivirus. I have compiled a great list of free but reliable and effective survival tools. I personally use all of them and also recommend them to my friends. The only commercial tool i use at present is the AntiVirus "QuickHeal" (earlier i was hooked to Kaspersky--but i found it was slowing my machine a bit) which i find very effective. After i use these tools, the free space on my harddisk increases and the computer performance also speeds up considerably.
1. Ccleaner It removes Internet temporary files, history and cookies. Unwanted registry entries left behind and the temporary files and log files created by various applications are also cleaned.
2. PowerTools Lite 2011 Along with registry cleanup, PowerTools Lite also clears unnecessary data from the registry, MRU, unnecessary temporary files and history data from all major applications and Windows itself to clean up the entire PC.
3. Microsoft Malicious Software Removal Tool Scans your computer for infection by specific, prevalent malicious software and removes the infection if it is found.
4. Anti-Malware This tool from Malwarebytes is quite effective and is to be used in addition to the regular Anti-Virus solution.
5. ZoneAlarm Firewall This free tool by Checkpoint is the best.
6. Immunet 3.0 This freeware Antivirus by ClamAV is good and be used in conjunction with other Antivirus products.
7. Secunia Personal Software Inspector This tool by Secunia reports about software patch/update status.
8. Portable Applications These applications increase security as these is no installation and hence no log files, dll files and registry entries on your computer. check http://portableapps.com/.
9. Sandboxie This tool allows to runs your applications in a sanboxed environment and hence if has some malware code then would stop them from accessing other parts of your computer.
10. McAfee Tools These free anti-malware tools remove malware, virus and rootkits.
11. VirusTotal If you have a suspicious mail attachment, file, web address or a software then submit them to the http://www.virustotal.com/ site for a multiple checks by the popular Antivirus solution vendors.
12. OpenDNS Use Open DNS (208.67.222.222 and 208.67.220.220) for connecting to Internet as it is more reliable and much faster. In addition you can also use parental control and other features if you register on the site.
13. Microsoft tools from Sysinternals Tools on this site would provide additional functionality. Do not forget to check out autoruns.exe to remove unwanted services and registry entries.