Yesterday, I was helping friend with his computer, which is slow. It's a new Lenovo. I used ccleaner to clean out the temp files and other junk. I also unchecked some startup items such as Nero InCD, QuickTime stuff, and yahoo stuff - all junk that start up at boot time. Nothing important was unchecked. We rebooted and everything was fine until today, he called me and said internet not working, can't do faster user switching.

I went to check it out and after a while noticed that the problem was all services had been disabled. Nothing was running. Then I asked him what he did after I left and he said he updated windows. There were 4 updates that were installed on 12/9/09 in add/remove. I uninstalled them thinking it could have been the updates, but it was not. There was no change after uninstalling.

Well, then I just started to enable all the services manually, the ones that I was familiar with and eventually got him back up and running. I probably missed a few.

My question is what could have done this if it wasn't the updates. Or perhaps it was the updates (anyone else had this issue?) He has Kaspersky Internet security so I'm thinking it's probably not spyware - but could be something not detected.

It's really bothering me that I don't know what disabled the services.

Updates wouldn't stop the services (not even code in them to do so), although malware or other could have set them to disabled or some such and the act of rebooting triggered it. Sounds like you might want to enable some auditing on said machine if you suspect further problems.