The plugin you are probably using is Subclipse. It should have an "Add to svn:ignore" option. If not, try updating to the latest versions of Eclipse and Subclipse. In general subclipse should be enough and there is no need for the command line.
For Windows XP I recommend Tortoise SVN. It integrates with the Windows Explorer and offers you a graphical environment for all your needs. I would say that is much more stable than subclipse and very easy to use.
If you do want to use the command line tools, download and install svn-win32 from here. The command line tools could be helpful in merge and copy operations.
I should also point out that none of these methods interfere with each other. You can work with Tortoise SVN or the command line and subclipse won't be affected. All svn clients work by writing and reading from hidden directories called .svn. There is one such directory in every folder under source control. As long as the svn client software is of the same version, an svn client can write to these hidden folders and another one will be able to read from it. A problem could arise if one of the clients is updated to a version that uses a different protocol for writing to the .svn folders. In that case, older clients won't be able to read the information stored there. Upgrading them to the latest version will solve the problem.