Hi,

In Start > Run box, type cmd.exe, hit enter key on the keyboard
In command prompt window, type SFC /scannow, hit enter key again.
Let SFC run and insert the XP installation disc to continue and if prompted.

See if there's improvement when finished.

As to McAfee after installing Adobe update, it is an optional third-party add-on/software from Adobe partners. Uninstall it, if you don't need McAfee Siteadvisor or anything it is installed from McAfee.
Next time you get any update, please uncheck any boxes in the installer window or webpage that only offers unneeded programs to update an application. It's their trick to earn money for each installation which is now a popular method by many software vendors even when only updating installed program.