Thanks Joudi, but I've done some more searching, and come up with a couple of things to try:-
1) Launch IE, go to Tools & then Internet Options;
2) On the General tab (which it launches to) delete cookies and temporary internet files, including all offline content;
3) Go to Advanced tab, lower right, click on restore defaults and click Apply;
4) Go to Programs tab, middle left, click on reset web setting, (recommend you deselect reset homepage);
5) Go to Privacy tab (if present), if Default Levels button is active click it;
6) Go to Security tab and for each zone set levels to Default Levels if said button is active; click OK.
If that doesn't work, then do all of the following, clicking OK after each:-
Start-->Run-->regsvr32 urlmon.dll
Start-->Run-->regsvr32 Shdocvw.dll
Start-->Run-->regsvr32 Msjava.dll
Start-->Run-->regsvr32 Actxprxy.dll
Start-->Run-->regsvr32 Oleaut32.dll
Start-->Run-->regsvr32 Mshtml.dll
Start-->Run-->regsvr32 Browseui.dll
Start-->Run-->regsvr32 Shell32.dll
I'll update this tomorrow, when I find out if anything has worked.