Go to google throme and tpye windows 7
Via Windows update
Windows Update.
if you have original windows 7 disc, you can reinstall it if you have recovery windows 7 disc, you can fix it
You just put in the installation disk for Win 7 and it will reinstall itself over the existing OS.
Update Win98 from the Microsoft website that should help.
Windows 8.1 can be downloaded and installed on a Windows 7 PC, but Windows 8.1 is not an update it is a new operating system. This new operating system can be bought from Microsoft for $119.99.
It can be regarded as both. It is an update on Windows 8.0 and could be seen as an upgrade on Windows 7 or older systems.
yes!
If you have windows 7 you can upgrade to it. If you have windows XP you will need to do a complete install.
Yes it can be rerun to preform an reinstall of the system.
it depends on what is wrong with it. you could reinstall vista or get windows 7 but that is only an absolute last resort.