Hi,
Here are some troubleshooting steps you can try that may help in resolving the issue.
- Start by uninstalling/reinstalling the wifi adapter.
- Open Device Manager and uninstall the wifi adapter. Reboot your laptop and it will reinstall the driver automatically.
- If it will not reinstall do try this link from Dell. It contains all the driver for your laptop just select the correct OS.
http://www.dell.com/support/home/us/en/04/product-support/product/inspiron-1525/drivers
- If all these will not work do a System Restore, restore it back to an earlier date or time before the problem even started happening.
- Worst case is you may need to do a complete factory reset.