Note:  I was preparing this text, accidentally erased it, and then discovered that Steve had posted details before I could retype it all...  but since I did retype it, here goes..

 

In order to fully answer your question, I need to rephrase it as two+ others:

 

1) MUST I have java present on my computer (in order for the PC to run and/or be secure)?

Answer:   No, Java is not a requirement in order for your PC to run.   But without it, if you visit websites that use java, you will not be able to view the java-based displays.   If you don't care about this limitation, then you can live without java --- and there are people who indeed do so.

 

2)  IF I have java present on my computer, can it impact my system's security?

Answer:  YES!  Unfortunately, hackers have been known to take advantage of "holes" in java [just like they exploit "holes" in Internet Explorer, and in Windows itself].   In particular, there is reason to believe that a "hole" in Java version 1.4.2_03 has been exploited by WinFixer.   As such,   if  you have java installed, it's important to keep it up to date with the latest version.   I prefer downloading the larger OFFLINE version, as it can be saved to your hard drive for later installation [at the time of your choice].  After completing the download, be sure to UNinstall   ALL  older versions of Java --- this is NOT done automatically upon installation of the new version --- and then install the new version.

 

3) So should I have java installed??   While not required, I think the huge number of legitimate websites that use Java strongly urge one to consider installing it, in order to experience the full richness of the media display.   So I personally choose to install it, on all my machines.

 

Note:   The same questions/decisions likewise apply to Adobe's FlashPlayer and Shockwave Player.

 

EDIT/Clarification:   While Java 1.4.2_03 might be one "hole" allegedly exploited by WinFixer [dictating that people update from this particular version]... be advised that updating java does not stop WinFixer from entering your computer by exploiting OTHER weaknesses in your system [or via bad surfing habits].