message with antivirus install that kb981889 is missing and to install

I unknowingly let my antivirus lapse for 1 week (i.e, no update happening). Had to uninstall and reinstall antivirus (Blink Professional with eeye digital security). During reinstallation, received message that said:

"KB981889 is not installed on this machine. PLease install this hotfix to resolve issues causing stuck network shares and RDP sessions as well as Windows kernel memory leaks."

I don't know what any of these things are, but I did check and found that kb981889 is not installed. Other things I read about hotfixes in general, though, said hotfixes are included in later updates and cautioned against using hotfixes. The PC does have all its updates. However, it has been running slow (which is why I discovered my out-of-date antivirus...I was checking things out) and not always finding in searches files that are in plain site. I've run utilities, defrag, scan disk. Things still aren't right.

I have an ACER ASPIRE 7741-7870, i3-370m processor, 2.4 Ghz 3MB L3 cache, 4 GB DDR3 memory, running latest Windows 7, 64-bit

Should I install this hotfix? Thank you!

If you have SP1 installed, then the hotfix is installed
If you don't have SP1 installed, then you should install it- and update it