Windows Vista and Defender

[Ollie56]

Good afternoon,

I am using Vista Premium on my pc (updated to Vista SP1) and I encounter regularly a problem after downloading updates for Defender.
One time out of four, after the download, I am not able to start the computer properly the following session as it doesn't boot.

I have to switch it off and on again and restart it (it will then check for solutions to the problem and most of the time restore the system at a previous point).

When I check in the "problem reports and solutions" area, I find the following kind of informations

Windows defender command line utility

Mp telemetry

Problem signature
Problem Event Name: MpTelemetry
Problem Signature 01: 80244016
Problem Signature 02: unspecified
Problem Signature 03: unspecified
Problem Signature 04: 1.1.1600.0
Problem Signature 05: MpSigDwn.dll
Problem Signature 06: 1.1.1600.0
Problem Signature 07: Windows Defender
OS Version: 6.0.6001.2.1.0.

Extra information about the problem

Bucket ID: 30031661

I tried to find answers on the microsoft website and other websites, contact the technical support (which suggest to start the computer in safe mode when it occurs) but not to avail

I am fairly confident in computing but I am not sure where the problem comes from. All I know is that it starts to appear after the download of the vista SP1

I can only guess that there is a problem with the setting of the start programs or some drivers (I was not able to upgrade some of them, who show the yellow triangle) and I was wondering if there was a way to correct this without going back to the factory settings.

thank you