If you find you can't uninstall the average application - a browser, say, graphics editor or word processor - then it's a nuisance, but no more. Windows and the rest of your software will probably go on working just as it always did.
If the uninstall fails for an antivirus tool, though, it's a different story. Security software makes many low-level changes to your PC, and if these can't be undone then your PC may become unstable, or behave unpredictably. Worse still, you may find you can't install any new security software because it detects the remnants of your old package, and demands that be removed first.
There's a simple solution to these problems, though - and it's called AppRemover. Run the program, choose the option to look for failed uninstalls, and it'll scan your Registry and hard drive looking for remnants of old security packages. Hundreds of packages are supported, from all the major security companies: AVG, Avira, F-Secure, Kaspersky, Lavasoft, McAfee, Microsoft, Panda, PC Tools, Symantec, and many more. The chances are it'll detect what's left of your security program, then, and you can have it removed in a couple of clicks.
Version 126.96.36.199 changes:
Enhanced support for [Avira GmbH] WISO Internet Security 10.x
Enhanced support for [Check Point, Inc] Total Security 13.x
Enhanced support for [Symantec Corp.] Norton Internet Security 21.x
Added support for [Agnitum Ltd.] Outpost Antivirus Pro 9.x
Added support for [Avira GmbH] WISO Internet Security 14.x
Added support for [Baidu, Inc.] Baidu Antivirus 2015 5.x
Added support for [Check Point, Inc] ZoneAlarm Antivirus + Firewall 13.x
Added support for [GData Software AG] G Data Security Client 13.x
Added support for [GData Software AG] G Data Antivirus 2015 25.x
Added support for [GData Software AG] G Data Total Protection 2015 25.x
Added support for [Lavasoft, Inc.] Ad-Aware TotalSecurity 11.x
Added support for [McAfee, Inc.] McAfee Software-as-a-Service 6.x
Added support for [Panda Software] Panda Antivirus Pro 2015 15.x
Added support for [Panda Software] Panda Internet Security 2015 15.x
Added support for [Panda Software] Panda Global Protection 2015 15.x
Added support for [TrustPort, a.s.] TrustPort Total Protection 14.x
Added support for [Trend Micro, Inc.] Trend Micro OfficeScan Client 11.x