I cannot even begin to advise you until we have certain information.
Do you have the Windows 7 DVD? Or, failing that, how did W7Ux64 get on the box? If you do have a DVD, where did it come from? Is the box new or pre-loved? Brand-name or OEM? (in the Aussie sense, local distributor assembles box from parts sourced all over, then uses Microsoft's OEM DVDs to install the OS. The dealer MUST include the DVD with the box on sale.)
In these cases, I'm reluctant to consider malware until we've eliminated Microsoft as the cause/result. I'm sure you've seen the sad stories of Redmond's failure to recognise legitimate installs, especially when it comes to updates.
Windows installer and maybe updater don't seem to be working windows 7 ultimate(64).
At fist I tried uninstalling a program and it came up with this message :
"The windows Installer Service could not be accessed. This can occur if the Windows Installer is not correctly installed. Contact your support personnel for assistance"
After some research I tried the Microsoft Fix it troubleshooter and that kind of forced the program to uninstall...but took hours for some reason. It did nothing for the fact that I still can't seem to download or update programs and that message comes up when i do try, like for example i'm trying to update iTunes and I THINK it downloads it...but still no installation. And now I can't even open my old iTunes it says :
"iTunes has stopped working, close the program/check online for solution"
Also whenever I try to install windows updates they always fail, including my most recent attempt, windows live essentials. Any questions? Please help I'm getting desperate...