Vista Fails to log on properly

[DanteX]

I have had my computer for about a week now and Vista has started not to log
on properly. When I log on it loads the desktop items and any start-up eg
Windows Live Messenger, but it then fails to load anything else. Programes
fail to start up, I cant search anything from the start menu search box, I
put one leter in and then it freezes and claims its loading something. Also
if I try to access the task manager instead of going to the blue option
screen after pressing cntrl-alt-del it goes black and has a error message
saying that windows logon failed to load security options. The only way i can
get it to work is to keep restoring it to and early date, however, the dates
are going further back before it works again. Can any one help?

My System Specs are:

Vista Home Premium 32 bit
Intel core 2 quad cpu @ 2.40
2GB Ram
1tb HD

 

[Andre Da Costa[ActiveWin]]

Go to Start > All Programs > Accessories and right-click
on the Command Prompt and choose "Run as administrator".
Type in: SFC /SCANNOW and press your Enter key.

If that does not work, try repairing your system. Boot from your Windows
Vista DVD, select the System Repair Option > on the setup screen, select
'Repair Computer > Select your installation of Windows > select Startup
Repair option and follow instructions.