can't install parallel tools

I am a newbie and am not able to install parallels tools. I have tried reinstalling parallels and XP and have not been able to install tools. I get an error message that install shield doesn't work, then an error that parallels tools can't be installed (on XP). I am not able to get online, so I can't fix the problem in XP. I have also tried to install windows 7 and have no luck there either (tools install, but none of the features that are suppose to be installed with tools are installed... mouse, crystal, coherence, folder sharing etc) I can see the tools in my library in mac OSX and install on osX. Any suggestions? So far I am REALLY unimpressed with parallels.