If she has old or ineffective antivirus software, I could suggest:
1) have her back up her important stuff
2) have her disable System Restore, wait for it to delete all the old SR points, then enable it again (which should set one Restore point) so she can back up if things go from bad to worse
3) locate her Windows CD and her license key in case she ends up needing them
4) uninstall the old antivirus, if any
5) install a 30-day trial version of
Kaspersky AntiVirus 7 and let it update, then reboot as prompted
6) open Kaspersky and click Settings at the bottom
7) go down to Threats And Exclusions and enable the Riskware checkbox
8) go back to the top of the Settings and set each of the modules in the Protection section and the Scan section to
Maximum
9) run a full Scan My Computer by right-clicking the red K icon in the system tray.
10) run a scan with the free version of Superantispyware:
http://www.superantispyware.com
That should be a good opening move, at any rate.

Results?