Most of the times we encounter archives with RAR extension which requires WinRAR to unzip them. WinRAR is not free and thus not an option for free software seekers or those who only have to unzip only a few files. There are free alternatives to WinRAR but those also have to be downloaded and then only we can open the archives.
Wobzip is a site which can convert RAR files to ZIP files easily and online. If you want to convert an archive from RAR to Zip, just to to http://wobzip.org/, if the file is in your computer, just browse it or otherwise give the URL of the online file which you want to download and press wobzip.
Wobzip will give you all the contents of the RAR file. If you want to download a single file from the archive, just click the file name and only that file will be downloaded leaving the other files in the archive.
If you want to download all the files, just press Download All Files As .zip button and a zip file will be downloaded to your computer. You can easily open this zip file using the built-in Windows utility. No need to go for an extra Zipping utility 
Access the Online Zipping utility here:
one thing about wobzip i got a virous from them (trogan horse)
Dear sir,
I have used your free online utility for conversion of .rar to .zip files and find it very useful. I express my gratitude for the help.
this is useful for all