Since more applications are involved, it may not be an Illy issue. If it is, you may try to restore the preferences, either Ctrl/Cmd+Alt/Option+Shift at startup, or Move the folder with Illy closed. The latter is recommended here because it is reversible and takes care or more issues, but requires a greater effort, especially the first time used. See explanations in the latter.
If you have Vista, remember to reboot before waking the beauty from her sleep.
Reinstalling does not replace the preferences.
When it is not something in the Adobe Illustrator CS3 Settings folder, it may be (with tests):
1. Corrupt font(s): you may move all fonts out of the Windows fonts folder (and move them back in);
2. Firewall interference (especially if more than one is running (XP SP2 adds one if activated)): you may turn them off (and on again);
3. Some versions of Acrobat generate many temp files. Too many (64K) causes the problem: you may search and destroy Temp files;
4. Some other inconsistency caused by Adobe Acrobat/Reader: you may try uninstalling and reinstalling (a newer version).
5. Incompatible/old printer definition file for the default printer: you may upgrade the driver, change the default, or set the PostScript driver/PDF to default;
6. Using a US/English version of Illustrator with Windows set to a different language: you may enter Control Panel>Regional and Language Setteings and change to English (and change back).
7. Quicktime/iTunes: uninstall Quicktime and make sure the Quicktime folder is deleted in the Program Files folder; and/or uninstall iTunes.
If none of these possible solutions work, have you made any (other) changes to the PC between succes and failure? New software loaded?
If it is beyond Illy, it may be necessary to reinstall the Suite or something. If so, a clean reinstall should be made, see http://www.adobe.com/support/contact/cs4clean.html.