Who is your ISP now?

Do you have a modem or router? Have a look for the brand & model

If reinstalling ZA & LW doesn't work, try changing Java versions. Some people have had connection problems with Java 1.6.0_01 & 1.6.0_02. You can either try updating to the latest version here (I have this one & LW's working fine on XP): Java SE Downloads
or try this older version, which has worked well for lots of people: Archive: Download Java 2 Platform Standard Edition (J2SE) 5.0 Update 11
Whichever Java version you use, download the JRE offline installer & remove any other Java versions before installing another one.