For some reasons when I'm trying to copy much information from any application to Excel/Word 2013 Office starts to work very slow and takes a lot of cpu resources, it can take for 2-3 minutes for copy/paste operation! GUI starts working incorrectly, as for example, you can select one cell in excel but it shows selection on the middle of the cells and so on. There is no problem I don't use copy/paste and office works perfect. With 2010 there was no any problem like this. 

Office 2013 Pro Plus. All updates installed. 32 bit under Windows 7 32 bit.

The system is running in virtual enviroment under Parralels 8.

There is no problem like this under Office 2010.

Anybody knows what it could be?

Many factors may cause the slow behavior. it might be a HTML format content or it might be included shape or etc.

See blog "What can cause slow copy and paste in Excel?"

http://blogs.technet.com/b/the_microsoft_excel_support_team_blog/archive/2011/09/08/what-can-cause-slow-copy-and-paste-in-excel.aspx

Tony Chen
TechNet Community Support

• Marked as answer by Daisy CaoMicrosoft employee, Moderator Tuesday, April 23, 2013 6:20 AM

The reality is that Excel 2013 under Win8.1 is an unstable mess. In my experience high cpu usage and freezing issues can be trigged by any of the following:

1) Opening a tiny file from email and selecting a group of cells. Observed dozens upon dozens of times. No the files are not special!

2) Copying a small number of cells.

3) Leaving an emailed file open for an hour and then reopening the window. 

4) Pasting data.

I've observed this behaviour have been observed mainly with xls files or xls files that have been saved to xlsx.

There is no apparent pattern to the behaviour and does not happen all the time. Therefore it is impossible to diagnose the problem by tweaking the settings, because you cant tell right away that you've fixed anything.

Due to the instability, Excel is now unusable for simple spreadsheet tasks.  I shudder to think what it would do when confronted with truly large or messy xls files. 

When will you consider the possibility that the problem lies with your own damned software and start working on a fix? No, instead you continue to blame add-ons and malformed files.