Microsoft .NET Framework 3.5-sp1 End of Life
Support dates and upgrade guidance — rebuilt from live data.
Supported
Microsoft .NET Framework 3.5-sp1 is actively supported. It reaches end of life on 9 Jan 2029.
884 days of security support left
89% of this branch's supported lifetime has elapsed — 19 Nov 2007 → 9 Jan 2029.
Check your versionreg query "HKLM\SOFTWARE\Microsoft\Net Framework Setup\NDP" /s
Support timeline
Official dates from the Microsoft .NET Framework release process.
| Milestone | Date | Status |
|---|---|---|
| Initial release | 19 Nov 2007 | — |
| End of life (scheduled) | 9 Jan 2029 | in 884 days |
| Latest release | — | current |
How much runway a newer branch buys
Microsoft .NET Framework 3.5-sp1 is the newest branch — this is the longest runway currently available.
| Branch | End of life | Days left | vs 3.5-sp1 |
|---|---|---|---|
| Microsoft .NET Framework 4.6.2 | 12 Jan 2027 | 156 | -728 days |
| Microsoft .NET Framework 3.5-sp1 | 9 Jan 2029 | 884 | this branch |
Frequently asked questions
When does Microsoft .NET Framework 3.5-sp1 reach end of life?
Microsoft .NET Framework 3.5-sp1 reaches end of life on 9 Jan 2029 — 884 days from now. After that date it receives no security fixes.
Is Microsoft .NET Framework 3.5-sp1 still supported?
Yes. Microsoft .NET Framework 3.5-sp1 is currently maintained. Latest release: —.
What happens when Microsoft .NET Framework 3.5-sp1 reaches end of life?
Security fixes stop. After 9 Jan 2029 this branch receives no further updates under standard support.
How long do I have to upgrade from Microsoft .NET Framework 3.5-sp1?
884 days. This is already the newest branch, so this is the longest runway currently available.