Not a problem, it'll just take us a bit longer.
Just do the stuff below, one thing at a time - and it'll get all the
drivers installed for you.
Any issues, just post back and we'll answer them as they occur.
Your system is an HP Pavilion a6750f Desktop PC
Most of the drivers are available from here:
Software & Driver Downloads HP Pavilion a6750f Desktop PC - HP Customer Care (United States - English)
Let's start with the video card drivers from nVidia. Here's the link for the drivers you need:
NVIDIA DRIVERS 270.61 WHQL
Click on the link to download, agree to the terms for downloading, save the file on your Desktop.
When the download is finished, double click on the file on your Desktop and follow the prompts to install the drivers.
Then, please notice at the HP link (above) that there are updates available for the Audio and Network drivers. But, we'll start with the
Driver - Original section and will do the updates afterwards.
In the Driver - Original section, skip the Original ATI Graphics driver (since you're now using an nVidia graphics card), then download and install the other 4 original drivers (Audio, Keyboard, Chipset, and RAID).
Then download and install the updates for the Audio and Network drivers from the Driver - Audio and Driver - Network sections.
Then, uninstall MagicISO. If you want to reinstall it, visit the manufacturer's website and download/install the latest available, Windows 7 compatible version.
Then do the same for the Microsoft Security Essentials program. Uninstall Microsoft Security Essentials. If you want to reinstall it, visit the manufacturer's website and download/install the latest available, Windows 7 compatible version.
Then visit Windows Update to ensure you have all updates. Then select the Important Updates and download/install Service Pack 1 (if not already installed)
Once that's done, post back with another copy of this stuff:
http://www.sevenforums.com/crashes-d...tructions.html (so we can check to make sure everything is updated).