In the January-March quarter, 93.9 percent of UK users had patched their Windows operating system, and 96.2 percent had patched other Microsoft software, such as Microsoft Office (PDF). However, 11.9 percent still had unpatched third-party software. The figures for the USA were slightly worse: 93.5 percent had patched the OS, 96.1 percent had patched other Microsoft software, and 12.7 percent had unpatched third-party software (PDF).
The major problems are Apple's QuickTime and iTunes, Oracle Java JRE, and Adobe Reader.
In the UK, for example, unpatched Java installations climbed from 36 to 41 percent compared with the first quarter of last year, and unpatched QuickTime installations increased from 55 to 61 percent. Fortunately, for most users, both programs can be uninstalled without a significant penalty. (Adobe Creative Suite users may have a QuickTime problem.)