Right click on desktop > personalize > windows 7
Select the windows seven theme and restart your computer. Or, you can try this,
Go to www.ccleaner.com
and download ccleaner.
Install it and run it. You are going to be in the first page of ccleaner. On the left hand side, check every thing except the last one (it has a word wipe in it) then click the run cleaner button and wait until it's closed make sure every application are closed Especially web browser. Once done, click on registry on the left hand side corner and click on scan for issues but make sure that all the options are Checked on the left hand corner. Once the scanning is done, if there are issues, click on fix button or if none close out of that. Better explAination on YouTube.