A friend of mine wanted to load windows 7 on our acer (aspire 5000) and told my it would not load because there was not enough memory he SAID something about moving memory around to try and get it in.He then INSTALLED his newer version of xp ,when i got back i could not connect to the internet.i tried to turn on the ethernet port light  on this laptop,but nothing seem to work ,so not having his disk i tried to install my older copy of xp it turned off right after it asked for the administrator pass word. it gets better LOL!!! i then tried windows 98 the original disk the unit came with,it stopped at a fatal exception 0E has occurred 0028:ff02847b.When i turn on the laptop I HIT f12 and follow the instructions .HELP!!!Absolutely, positively no idea what you're talking about....
You tried to turn on the ethernet port light?
Moving memory around?
Installed his newer version of XP? Over what?
You tried to install an OLDER copy of XP?
You then tried Windows 98?

I honestly have no idea what you've done (or why) or what is currently on your system.I reloaded windows 98 then used the 4 recovery disks some how I have the newer version of xp that my friend put in,also, now i have the enthernet port light back on ,and everything is working again.??Happy ending We need clear information.
You have a version of XP that was working good on this Laptop?
Next you went to install Windows 7 over it and it failed?

Did you use the recommended method of doing a fresh install of putting Windows XP onto a laptop that had Vista or Win7.

Microsoft and this forum have warned users that an install of Windos XP on a Hard Drive that had Vista or Win 7 will fail. Unless you follow the specific instructions.

Here are the general instructions that should work in most cases. (Some details will not apply.)
http://support.microsoft.com/kb/313348

If you did that and it failed, please note the error, if any, and come back here.