The Twitterverse has been a busy place this week, and it's not all been about X Factor! There's been plenty of tech issues that web users have been discussing too, from Microsoft announcing it will make the Windows integrated app store available in the beta version of Windows 8, which is due out next year, to the EU's investigation into Apple and the price fixing on eBooks. Here's PC Advisor's five favourite tweets of the week.

EU to investigate Apple over eBook pricing

The EU revealed this week it is launching an investigation into Apple and five publishers over the price of eBooks. Hachette Livre, Penguin, Harper Collins, Simon & Schuster and Verlagsgruppe Georg von Holzbrinck are also being investigated by the European Commission, which is concerned the firms may have "engaged in anti-competitive practices" regarding the price of eBooks, "possibly with the help of Apple", which breaks EU antitrust regulations.
"Uh oh... EU to investigate Apple over eBook pricing," we said in a tweet.

Group test: what's the best encryption software?

We've pitted some big name encryption software against each other to discover just which is the best.
Editor MattJEgan tweeted: "What have you got to hide? Encryption software group test".

Microsoft to preview Windows app store next year

Microsoft revealed this week it will offer the first look at the app store integrated into Windows 8, the next iteration of the operating system, in February next year. The Windows Store, which will appear for the first-time in the Windows operating system, will offer PC users the chance to purchase apps for the Metro interface and the traditional desktop.
Deputy news editor CarrieSkinner said: "Microsoft to preview Windows app store next year".

Win £250 of Amazon Vouchers by voting in the PC Advisor Reader Awards

We love our readers so much that we're giving you the chance to win £250 worth of Amazon vouchers for having your say in our 2012 PC Advisor Reader Awards.
"Win £250 of Amazon Vouchers by voting in the PC Advisor Reader Awards" we said in a tweet.

Google Android app store hits 10 billion downloads

Google revealed this week more than 10 billion apps have been downloaded from Google's Android app store, since it opened in 2008. Furthermore, in celebration of the milestone, the search engine has discounted a number of apps to just 10p.
"Google Android app store hits 10 billion downloads!!!" we tweeted.