Hi, here are some common things to try, partly stolen from other posts on this forum, CalamityJane and others

Certain security software all running at the same time can cause conflicts. A number of Adaware users who also are running SpySweeper have reported that disabling SpySweeper during an Adaware scan has resolved that conflict. ---SpySweeper has a new update which is supposed to fix this issue, so update now if you run spysweeper---
To temporarily disable SpySweeper, right click the Spy sweeper icon in the notification area (right side) of the system tray and choose shut down.
Try scanning again with Adaware, it should be able to complete the scan.
To re-enable SpySweeper, start it again from Start > All programs > Webroot > Spy Sweeper.
Make sure you're updated to the latest version of Ad-Aware, which is 1.06, and download the latest definition files, from 15.08.2006
Do a disk cleanup to clear the browser cache and other
unnecessary files.
Go to Start > Run and type in the box: Cleanmgr
Wait while Windows scans your system for files to delete.
Make sure these 3 are checkmarked and press *ok* to delete them.
Temporary Files
Temporary Internet Files
Recycle Bin
Open Ad-Aware, Click on Settings (The cogwheel icon), Choose
"Tweak -> Scanning Engine" and Deselect the "Unload recognised modules
during scan" option
Try scanning in safe mode. Access Safe Mode by (usually) pressing
F8 during the boot process and choosing safe mode from the menu.
If you still have problems, cancel before the scan reaches the
point of stalling -- for example, after 20 objects are detected. Click
?Cancel? on your log file. Remove any objects you want and rescan.
Again, stop the scan before it reaches the point of stalling and remove
any additional objects. Then try a full scan without stopping it.