|It probably won't work but try starting in Safe Mode. |
If you can get there you might be able to fix it.
Tap F8 whilst booting and you should get a menu. Choose Safe Mode. If you make it, you will get desktop with words safe mode at each corner. The graphics will be lousy but it would be a start.
Assuming it doesn't make it to Safe Mode then choose one of the Command Prompts from the menu instead. When you get to the black screen do this:
dir c:\explorer.exe (hit Return key).
dir c:\windows\explorer.exe (hit Return).
Note what happens in each case.
In the first instance it should find nothing. If it finds the file there it's a virus and we can try deleting the file.
In the second instance it should find the file. Give us the details of its size and date.
While you are at the command prompt do this:
Type ver (hit Return). This should give your Windows version. The idea is to find out if it is W98 first edition or second edition (unless you know this for sure).