You may be knowing that there are built-in tools in your operating system that can be used to remove the evil software. Almost all the browser provide some sort of security tools including anti-phishing filters or anti spy-ware protection, Plus they block those website which are potentially harmful for your system. You can use those features they won't slow you down.
Know that there are plenty of people, though, who hate anti virus software and with good reason. Most of them are hogs, slowing down your system and corrupting especially OS files. Secondly, Free anti virus programs do not provide a good level of security and premium version are expensive too so why not go without any anti virus program.
Use clean software
A clean software not an anti virus program. These are light programs that are used to delete temporary files, history and other unnecessary files which are not used by system but still create a load on OS. Remember that living without anti virus means living without scanning so if you download a files it may be harmful for your system so better to use some some best disk cleaner software.
Scan you PC remotely
If you have more then one PC, You can install anti virus on one while leaving the other machine without anti virus software. If the two machine can see each other on the network.
Or you could take advantage of free online virus and spy ware scanner tools. Trend Micro's House call ( http://housecall.trendmicro.com) and Eset's online scan (http://www.eset.com/onlinescan ) these will help you to perform a scan of your computer right from the internet. such scans might not remove any virus or spy ware found but they will at least tell you that your system is infected.
Manual remover of virus
There are many tips and tricks which are used to remove the virus manually as you can see how to remove readme.eml virus manually. If you know how to edit your registry then you can delete the key which is associated with infected file or virus plus you can follow few other tips how to increase you system speed.
Stop unwanted window process
You may not be knowing that there are few process running on your system which are hidden and don't show anywhere not even in task manager even sometimes they can disable you task manager. so its very necessary to stop these unwanted windows process.You can see more detail on how to Stop unwanted window process.
Backup all your drivers
When a virus attack on your system its sometimes tries to damage the driver files so when you are without any anti virus software you need to backup all you drivers. Hopefully these tips will help you speedup your system.
