As we found out with the pic upload function here a while back.....
The version of Windows being used reflects the version of Internet Explorer (or other browser) i.e. the latest IE version is ver 11 it does not work on on Windows Vista.
Unfortunately if you are using earlier versions of Windows, the latest Apps, Plugins and things like Flash may not be compatible.
I am a retired CAD Manager, Systems Administrator and Network Manager. here's a few things you can do to help regardless of Windows Version. If you don't know how use "Help" or ask here.
IE or other - Delete all - History, Cookies and Temporary files. This needs to be done occasionally as they just build up and up. (I've seen a common use office internet terminal's hard drive totally filled to the point it would not boot, there is a fix if this happens.
Computer or Laptop - Check things like Virtual Memory Size (SWAP File) and ensure you have enough Hard Drive space for it. (explained in simple terms; A PC has a fixed amount of RAM to operate, some Apps require more, so the PC caches what is in RAM and not used at a moment in time to a "SWAP" file on the disk. If the drive is near full, then there may not be room for the SWAP file and things slow down or "Crash"
There are various utilities with Windows, one is Disk Cleanup. Use it to get rid of unwanted and unused files. (These are operating system files, not your DATA)
As said, DEFRAG the drive/s you have, this compacts files that have been spread all over the disk into a smaller area and make the PC go faster.
I probably did not have a day go by at work, when someone would have a PC, printing, email, internet or application problem. To try to find and fix most of these is time consuming and may never be found. My work around was easy and in 99% of cases fixed the issue (with no rhyme or reason)
FIRST THING TO DO WITH ANY PC PROBLEM - SAVE ALL DATE IF YOU CAN, CLOSE ALL APPS IF YOU CAN, CLOSE DOWN IF YOU CAN - IF ALL ELSE FAILS PRESS THE MAJOR RESET BUTTON. and REBOOT.
WHAT IS THE MAJOR RESET BUTTON? IT'S THE ON/OFF SWITCH