Vista was a real pain when it first came out. It was bloated, buggy and slow.
My son's machine came with Vista and I ended up putting XP on it. After he managed to mangle his files up to a point where I wasn't going to waste time working out what he had done, I used the restore disks to format the hard drive and put Vista back on it. Then I download all of the updates that had come out over the years and discovered that the performance was more or less what I got with Windows 7 (although 7 was still more friendly with older software).