Windows 7 and Windows Server 2008 R2 include a new virtual Wi-Fi access point (AP) feature called Wireless Hosted Network. The default IP used by Windows is 192.168.137.1. However, you can change this IP to something else via Widnows Registry changes:
Hive: HKEY_LOCAL_MACHINE
Key: \SYSTEM\CurrentControlSet\services\SharedAccess\Parameters
Name: ScopeAddress
Name: ScopeAddressBackup
Name: StandaloneDHCPAddress