I am currently using windows 7 ultimate and i want to upgrade to windows 8. Can i upgrade directly or i have to replace windows 7 and install all the softwares once again which are currently present in my windows 7.
Please Someone help me...

Please Someone help me...
My Computer
At a glance
Windows 7 Ultimate x862.99GB RAM326MB
- Computer type
- PC/Desktop
- Computer Manufacturer/Model Number
- Custom Build
- OS
- Windows 7 Ultimate x86
- Motherboard
- Intel
- Memory
- 2.99GB RAM
- Graphics Card(s)
- 326MB
- Hard Drives
- 180GB
- Antivirus
- Quick Heal Total Security 2013
- Browser
- Google Chrome