This happened today

[Toby570]

I realise these symptoms may be conditional and peculiar to my system but I shall list them anyway. I shall be as brief as possible.
Powered up and windows started normally, entered password and went to the welcome screen. This is where the problems began.
After 5 minutes the welcome screen faded to black and I was left with the mouse pointer to play with.
Restarted in safe mode with networking to see if I could visit here and get some advice. Same thing, black screen and the mouse, but it did have safe mode displayed on the corners of the screen.
Several restarts later and I managed to reach my desk top.
System event notification service failed to start, this prevents me logging on as an administrator apparently, I forget the precise wording.
No connectivity, The dependency service or group failed to start.
Kaspersky could not start some protection components.
Firefox has encountered a problem and has had to close.
I tried a system restore but was told - No back up points are present to restore system to.
During one of the many restarts I ran a full scan with Malwarebytes in safe mode but it found nothing.
Eventually the computer allowed me to do a system restore, after which everything was back to normal, except Firefox 10. That's also the only thing I've downloaded recently.

Question is.. was that the problem? could a browser cause so many problems?
If not, what do you think happened here, because I don't want a repeat performance of this.
As a precautionary measure I'm now using an older version of Firefox and disabled automatic updates for it.
Vista Home Basic 32-bit SP2 AMD Sempron 140 processor 2.0GB Ram and is just over a year old.(if that helps!)

Many thanks.

[Wak]

If you've got it working again, Toby, the first thing I would do is to make a Restore Point for future use.
I would then check the System Files as below:_
http://support.microsoft.com/kb/929833

[Toby570]

Thanks Wak, I've run the scan and it reports a clean bill of health.
Windows resource protection did not find any integrity violations.
So whatever the problem was, I suppose will forever remain a mystery. Useful trick to know though, I've made a note of those instructions in case I ever need them again.

[ummmm]

Same happened to me on my PC. It corrected itself and hasn't happened again.

[AlBags]

Firefox will not cause those issues.
An AV Program could well cause it.

.. and it IS Vista! : )

[Toby570]

Only have Kaspersky and Malwarebytes AlBags...
...And I know...Tell me about it!