How to Enable Auto Logon to Windows XP and Vista Joined as Domain Member

  1. Click Start, click Run, type regedit, and then click OK. In Windows Vista, simply type regedit in Start Search and hit Enter.
  2. Navigate to the following registry key:HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Winlogon
  3. Double-click the DefaultUserName entry, type the user name to log on with, and then click OK.If DefaultUserName registry value name is not found, create the new String Value (REG_SZ) with value name as DefaultUserName.
  4. Double-click the DefaultPassword entry, type the password for the user account under the value data box, and then click OK.If there is no DefaultPassword value, create a new String Value subkey (REG_SZ) with DefaultPassword as the value name.

    Note that if no DefaultPassword string is specified, Windows automatically changes the value of the AutoAdminLogon registry key from 1 (true) to 0 (false) to turn off the AutoAdminLogon feature.

  5. In Windows Vista, DefaultDomainName has to be specified as well, else Windows will prompt of invalid user name with user name displayed as .\username. To do so, double click onDefaultDomainName, and specify the domain name of the user account. If it’s local user, specify local host name.If the DefaultDomainName does not exist, create a new String Value (REG_SZ) registry key with value name as DefaultDomainName.
  6. Double-click the AutoAdminLogon entry, type 1 in the Value Data box, and then click OK.If there is no AutoAdminLogon entry, create a new String Value entry (REG_SZ) with AutoAdminLogon as the value name.
  7. If exist, delete the AutoLogonCount key.
  8. Quit Registry Editor.
  9. Click Start, click Restart, and then click OK.

After computer reboots and Windows XP or Vista starts, system can log on automatically to the preset or predefined user in the registry.

Difference between WCDMA and HSDPA

1. HSDPA uses WCDMA with 16 QAM modulation technique and original WCDMA networks use QPSK as the modulation scheme.

2. WCDMA fro 3G networks are capable of providing data rates up to 2Mbps and HSDPA is capable of proving downlink data rates up to 14.4 Mbps.

3. Fast HARQ (Hybrid Automatic Repeat Request) is being used in HSDPA networks and traditional WCDMA networks don’t use this feature.

4. HSDPA hand sets are categorized in to 12 according to TTI, Transport Block Size, modulation schemes etc used for HSDPA networks and WDMA networks doesn’t categorized like that in original 3G network deployment.




1- GSM: 2G Europian standard and the first digital mobile system. It offers only circuit-switched traffic (i.e voice calls, SMS…etc) and data transfer at very low bitrates 9.6kbps.

2- GPRS: also reffered to as phase 2+. It offered packet-switched traffic with new network components integrated over the existant GSM core network. This allowed data bitrates to increase to 171kbps. It is also considered as the first step towards 3G networks.

3- EDGE: It was made to cover the delay of delivery of 3G/UMTS network. It supported data rates upto 384kbps.

4- UMTS: the first 3G Europian standard network. It is the optimal solution for GSM operators to support 3G services. The Air interface technique used for this network is WCDMA. This technique allowed data rates to reach 2Mbps.

5- HSDPA: It is actually a software upgrade to the UMTS network using the same air interface technique used in UMTS (WCDMA) and supporting data rates upto 10Mbps.