This maybe an error with your web browser.
The code is working perfectly on my web browser. Just tried it on Chrome web browser. I don't know why you added that semi-colon at the end of your code:
<form action='upload.php' method='post' enctype='multipart/form-data'>
Select file to upload:
<input type='file' name='fileToUploadNep'>
<input type='submit' value='submit'></form>
;
The code is working properly. Ask the developer of your web browser.
Screenshot, taken from my computer...
If you have another form on the web page and wants to hide one of it's input element, just simple hidden class to it and in your CSS file, add .hidden{display: none} and that's all!
or, the simplest way is to add an inline style to the input.file element. It'll override the style, written on your CSS file.
Sample: <input type='file' name='fileToUploadNep' style="display: inline-block">