If you have a large blank space in Add/Remove Programs, it is usually due to the DisplayIcon registry value for an item having a negative number. Go to Start > Run, type regedit, press Enter and navigate to
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Uninstall. Scroll down the sub-keys in the left pane and, if present, look at the corresponding value of DisplayIcon in the right pane. If the end of any of the lines has a negative number, say -1, right-click and Modify it to 1 (one).

Alternatively, if Add/Remove is never populated (it can take some time):
1. Go to Start > Run > type REGSVR32 APPWIZ.CPL (capitals for clarity only, also note the space) and press Enter. Then again Start > Run > type REGSVR32 MSHTML.DLL and press Enter.

2. If 1) is not successful, try this but create a system restore point first just in case anything goes wrong.
Go to Start > Run, type regedit, press Enter and navigate to registry key HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\App Management
In the left pane, right-click ARPCache and delete it. Reboot the computer.
NOTE: The ARPCache key is where Add/Remove stores the details of programs that show in the list but it doesn't remove the details when you uninstall a program. If you look down the list (before deleting it, of course) you will see all the Windows updates as well as old programs. After deletion, the key will be recreated by Windows.

3. If 2) is not successful or you can’t access regedit I suspect that you have caught something nasty.