This site (LinuxQuestions.org) doesn't generally deal with Windows problems, so you may get better help on a Windows forum. How did you end up here in the first place?
That being said, someone here may be able to help, but you're going to need to give more info. What do you mean by "vertical typing line"? Do you mean the cursor? Also, does this happen in one application (e.g. a word processor, web browser, etc) only? Is the machine a laptop? If so, is it possible that you're inadvertently pressing on the touchpad? Perhaps you had it disabled before and Windows 7 has enabled it?