A friend with a Dell Vista Home Basic desktop PC (Inspiron 518, 32-bit) has had 'page not found' errors occurring at about a 50% rate in both IE8 and Firefox. He uses AOL webmail and even when the main page displays he is almost never able to actually display his Inbox - he just gets the 'Loading Mail' screen with the blue circle which eventually gives way to 'Problem accessing your webmail - try later'.

His ISP is Comcast and they have come out and rewired his connections, both outside and in. They have hooked up a new modem (he is NOT working wirelessly), and their efforts have not made a bit of difference.

I have run sfc /scannow, Full MalwareBytes scan, TDSSkiller and chkdsk /r /f. No change.

He just bought a new 64-bit Windows 7 Home Premium laptop and I hooked it up for him, using the same cable and same modem he'd been using with his desktop.

Everything works perfectly.

I reconnected his desktop. Same bad behavior.

I brought his desktop tower to my place and connected it to my modem (my ISP is Windstream). It works perfectly with my equipment. I had 6 IE and 2 Firefox Windows open and tried to access his AOL mail, and it came up instantly.

I am at a complete loss. I really don't know what to attempt next. Although I'm perfectly willing to reinstall the OS, I have no idea if that will correct the problem.

Any ideas? Thoughts? Has anyone ever encountered behavior like this? Where a PC is slow and gives a lot connection problem pages through one ISP, but works perfectly with another? And another PC works perfectly with the original provider?

I originally had this problem with a Dell Inspiron 518 Vista Home Premium tower
Unusual & Perplexing Page Not Found Behavior

I decided to reinstall the OS, but I could not get the PC to boot off the CD - F12 to change the boot order or F2 to access Setup did nothing. So I ran Windows Vista setup from within Vista which created the folder Windows.old on the C: drive.

The first weird wrinkle was that I could not access the internet - the was a yellow ! on the network adapter in device manager. Uninstalling it and letting Windows reinstall didn't help, so I downloaded what Dell said was the correct driver - Realtek RTL8168C (the one w/ the yellow ! lacked the letter C). Once I fixed that I could connect.

Then I noticed that I couldn't right click on an empty area below the address bar in IE - I wanted to get the Menu Bar and remove the Favorites Bar. Right clicking did nothing. The mouse works fine, and I can use the right mouse for other things - right clicking Computer, then left clicking properties, righ-clicking a document, then left-clicking Explore, or Open, etc.... I did get the bars fixed by left clicking Tools, then Toolbars, and checking and unchecking what I wanted, but right-clicking on the Menu Bar still does nothing.

I also cannot send shortcuts anywhere. I used to click File\Send\Shortcut to Desktop to get a desktop icon for my email. I can do those steps, but no shortcut appears. I had to drag from the left of the address bar to the desktop to create a shortcut.

I cannot open a folder anymore without it opening in a new window - the option in Control Panel/Folder options is set correctly, and I even checked the registry. I dunno - it's got the right valuesin CabinetState.

But the biggest problem is that I cannot download... usually. I easily downloaded Security Essentials, but when I tried to downloader Adobe Reader X nothing happened. No little clickable bar below the tabs line at the top, no download box. Same thing happened with Malwarebytes from CNET. That one l downloaded using a thumb drive on another PC. It installed perfectly, and found no errors on a full scan.

I also ran sfc /scannow which found no integrity violations.

Do I have to reinstall again? And how do I do it (see paragraph 2)?

Thanks, but I don't know how to do a clean install since I can't get the PC to boot off the CD. I mentioned this in the beginning of my post. I get the Dell screen which says F2-Setup and F12-Boot menu, but F2 and F12 no longer work - the PC just boots normally. If I pull the plug I can get the system to go into Startup Repair - it's been there now for about 10 minutes with the blue indicator going from left to right while it says 'Startup Repair is checking your system for problems...' 'Attempting repairs'.

And then, of course, I got Startup Repair cannot repair this computer automatically. After which I could, of course, boot normally. But, of course, I still cannot boot from the CD.

How do I set it to IDE, please? See, the only way I know to do that is to get into the BIOS, and the only way I know to get into the BIOS is by using F2-Setup on a Dell PC, and since F2 does nothing on this PC I'm in a bit of a quandary. Hence my post to this forum.

I went back to IE7 and I can now right click, can now download Adobe Reader X, and can send shortcuts to my desktop. Needless to say it did nothing for my inability to access the BIOS.