Typing one letter or character in a geoprocessing tool text box in ArcGIS Desktop causes four of the same character to appear in the text box.
This is a known issue on Windows 64-bit operating systems and is triggered after editing a model in Model Builder.
To resolve this issue, use one of the following workarounds:
- Close and re-start the application. This resolves the problem until the next time a model is edited in Model Builder.
- Download and install Service Pack 2 for Windows XP Professional, x64 Edition. See the link in the Related Information section below.