Performance of ArcGIS may be negatively affected depending on the operating system it is installed on and the resources allocated for it. In cases like this, one suggestion to help increase performance is to add a Spatial Index to the data. ArcGIS uses these spatial indexes to quickly locate features in feature classes.
To add a Spatial Index:
1. Start ArcCatalog.
2. Navigate to the location of the shapefile.
3. Right-click the shapefile and select Properties.
4. Select the Index tab.
5. Click the Add button in the Spatial Index section.