Backweb is a background downloader program... before you panic, it might not be as bad as it sounds... HP, Compaq, IBM, Logitec, Kodak, F-Secure, among others, use the program.... It's usually big corporate giants who use it to update, etc... in the background while you're online. So, technically it's spyware, but I'm unaware of it being abused (it's quite an expensive piece of software, apparently, so most net trash type companies can't afford it).
It can be uninstalled, usually by just going to Add And Remove programs... now, just what effect that will have on your computer is questionable... if, for example, your new computer is using it to keep itself updated, or your virus protection is using it to keep it's definitions up to date, or... you get the idea. If you know what program is using it, you can get a better idea if you need it or not (you can sometimes tell by what directory the program is running from).
Now, if you're getting errors every bootup, the file is damaged, or has been removed by an over zealous spyware removal program. so, to get it working properly, you need to reinstall the original program it came with. To get rid of the error alone, you can click Start/Run, and type in msconfig and click ok. Go to the Start up tab, and take the check out of the listing for it, and reboot.