Try opening task manager>new task>cmd a black sceen will appear behind task manager.Close task manager and on the black screen at the cursor type "C:\WINDOWS\System32\winnet.dll" without the quotes then press enter.
Do the same for these:
C:\WINDOWS\System32\taskmgn.exe
C:\WINDOWS\System32\telnetxp.exe
C:\WINDOWS\System32\winnet.ini
Reboot the computer.
IF it will start.Please post a Hijack This log so that the files associated with the virus/spyware/hijacker can be identified. You can download Hijack This at this link http://www.tomcoyote.org/hjt/ then place it into a folder of it's on, such as C:\HJT, so that back up copies can be made and not clutter your desktop or other folders and the backup copies of deleted items can be easily located if needed.
Once saved double click HijackThis.exe, and press "Scan". When the scan is finished, the "Scan" button will change into a "Save Log" button.
Press that, save the log, Ctrl-A to Select All, and copy its contents into the text editor at this forum.
Do not fix anything yet unless you know what you are doing. This is a powerful tool that can crash the computer if used improperly.