It is possible to disable superfetch, but first of all I'd recommend reducing the number of items on startup: msconfig >> startup tab.
It is also a good idea to disable a few services you never need in Control Panel >> Administrative >> Services. Of course, this step must be done thoughtfully.
You also mentioned boot and stop error messages, check your C:\Windows\Minidump folder, if not empty then copy out, zip, and attach the .dmp files.