Everything onscreen becomes very LARGE

[dtc]

When I turn on my PC (HP Intel Pentium Dual 4.00 MB...Windows Vista) the size of everything onscreen becomes very large quickly in (3) increments. Most of the icons are offscreen. When I switch to the other screennames, the size is normal. I had successfully used System Restore before but it doesn't work on my screenname now and sometimes makes the other screenname items large also. I don't know how to pick a 'valid' previous restore point without just guessing.
I tried the suggestion here of going to Graphics Properties-Display Settings-Advanced Settings and setting Horizontal size to 0 (from 80) but it keeps reverting to 80.
I changed the Screen Resolution from to 800x60 to 1024x768 and it helps somewhat but it is a little blurry. 1152x720 seems a little better but do I really need to do that?
Sometimes when the cat touches the keyboard the enlargement happens. Is there a key(s) that can cause this? Are there keys that can correct it?
Thank you! DTC

[ksmic]

IDK maybe u have a graphic prob. Next time keep ur cat of the computer. U dont know wat might happen next.

[computerhelpmaryland]

Any chance of getting a screenshot of this? Just hit the screenshot button and paste it into the paint program then save it to desktop the paste it here...

[dtc]

Thank you. Actually it's more often something I'm doing to cause this by handling the keyboard maybe. I thought I had solved the problem by going to Graphics Properties, then Display Settings but the option of 1440x90-60Hz is usually not available in the list under Screen Resolution. The options skip from 1280x1024 to 1400x1050. Set at 1400x1050, a warning comes stating  'Input Signal Out of Range  Change settings to 1440x900-60Hz'. Sometimes that option appears in the drop down menu but usually not. It won't allow setting it manually here.

[Broni]

Try to reinstall your video driver.