What is your OS ?
What were you doing when you get the error ?
Try a repair of avast. Add Remove programs, select 'avast! Anti-Virus,' click the Change/Remove button and scroll down to Repair, click next and follow. You need to be on-line to do this.
About the "usigetskin failed" issue, if the avast! repair does not solve it:
You will have to register ACTSKIN4.OCX
Follow the instructions:
Select START -> RUN...
Enter the following command:
If you have Windows NT or 2000:
C:\WINNT\SYSTEM32\REGSVR32.EXE ACTSKIN4.OCX
If you have Windows 95, 98 or ME:
C:\WINDOWS\SYSTEM\REGSVR32.EXE ACTSKIN4.OCX
If you have Windows XP:
C:\WINDOWS\SYSTEM32\REGSVR32.EXE ACTSKIN4.OCX
If you have Windows x64:
"C:\WINDOWS\SysWOW64\REGSVR32.EXE" ACTSKIN4.OCX
Press OK (or Enter).
A message saying that the file was successfully registered should appear...
For some reason, ActiveSkin (the 3rd party library avast uses for skinning) does not seem to be working on your system. As a workaround, we may disable skinning in avast - that should solve the problem. Program Settings, Common, and uncheck any option with skins mentioned (see image, avast-no-skin).
If you are unable to access the above you can do this manually. To do that, open the file <avast>\data\avast4.ini, look up the [UserInterface] section, and add the following entry: StartWithSkin=0
