Freeing up disk space doesn't affect your computer's performance. That's
not why you run the Disk Cleanup Wizard. You use Disk Cleanup to free up
space so you can store more on your disk.
You increase your computer's performance by adding RAM or by closing
memory-intensive applications.
If you have a question about 'Internet Explorer must close' messages,
ask in the Internet Explorer newsgroup. Usually that's caused by an
incompatible browser add-on or malware.
The minidump files are automatically generated when Windows crashes.
They are used by technical support representatives to help understand
why your computer crashed. If you're not planning on submitting them to
a support rep, erase them.