I use codestuff starter, which is an easy way to do what you've been doing manually.

It will allow you to delete/disable/re-enable startup items, whether they're in your registry, startup menu etc.

It won't tell you what can be safely disabled.
In fact I would suspect any program which did claim to be able to do so, because many .exe file names have been duplicated by virus writers, and it would be difficult for a program to tell this just from a filename.

However, starter will assist you in doing the lookup, and it takes you to a good site which describes the likely sources of each file and whether you need it or not.

see this site for some extra tweaks

1. 1. Black Viper's Web Sitecopy