my thorough scan seems to hang

[lookbehind]

 ???I have tried to do a thorough scan twice but after 2 to 3 hours it isn't finished. Actually, each time the scan appears to hang at a particular program which is 525MB large. Incidentally this file is scanned at different times within the scanning process,i.e scan#1 it may be dile 30000 and scan#2 45000. Is it just the size of the particular program that is causing a problem? Now nothing has happened for well over 3/5 hour and it could be more as I have been out for over an hour before.

[Lisandro]

I can't help you more but I think it will be useful if you say the extension of that programs if they're not *.exe
How many free space do you have in the HDD?

[lookbehind]

I don't know if this may help;-

Program consists of  55 files 3 folders
Starts with .exe file. Other than usual .dlls there are
  796 KB of files with .aw and .wtr extensions
      4KB .psi / 13203KB .dat  / 4100KB .dct  26541KB .vlf  / 99086KB .its / 185KB .ndx

Disk used 16.1GB / unused 58.3GB

Actually the profram is microsofts Autoroute express 2001

If this is the program causing the hang are there particular items, e.g files with particular extensions it would be safe to exclude? Can you also enlighten me why, as I said in OP, the sequence of files scanned appers to change?

[Eddy]

run chkdsk and defrag. Than try to run the scan.

[igor]

Maybe some of the files is actually a big archive. Try to turn on the creation of the report file in program settings and let the "OK files" be included there (the report will probably be rather huge). During the scan, you can check the end of the report file being created - you'll see either what is going on, or where it got stuck.

[lookbehind]

Thanks all for the tips, though. Igor, I couldn't access the file you mentioned. Perhaps I was not going about it the right way. In the end I decided to uninstall Autoroute as it can be installed to run from CD and will take up less space. The scan became very slow still through the files I mentioned previously.

A typical file name  and path is -214062498.DAT
C:\Documents and Settings\user name\Local Settings\Temp\_avast4_\unp15281511\0x00

What are those files and are they essential as without them being on disk scans would be much quicker.

[Lisandro]

C:\Documents and Settings\user name\Local Settings\Temp\_avast4_\unp15281511

All files is this folder are temporary ones.
They come when avast unpacks the archive files and scans them.
You can delete them all.
After deleting them, can you identify the file which delays the scanning (the one which is being scanned at that time)?